Resonation device, oscillator, electronic apparatus, and moving object

ABSTRACT

In a crystal resonator, a resonator element is installed in a package via a first bonding member and a second bonding member, and when viewed from above, a distance between a first bonding center and a second bonding center is set to be L1, and a length of a perpendicular line drawn to a virtual line which connects the first bonding center and the second bonding center from the resonation area center is set to be L2, a relationship expressed by 0&lt;L1/L2≦0.97 is satisfied.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/988,158, filed Jan. 5, 2016, which claims priority to Japanese PatentApplication Nos. 2015-000676, filed Jan. 6, 2015, and 2015-000680, filedJan. 6, 2015, all of which are expressly incorporated by referenceherein in their entireties.

BACKGROUND

1. Technical Field

The present invention relates to a resonation device, an oscillator, anelectronic apparatus, and a moving object.

2. Related Art

In a communication equipment industry, in order to obtain a stablefrequency signal, a resonation device such as a crystal resonator and acrystal oscillator which output a desired frequency signal by using aresonator element which is formed of a piezoelectric substance such as acrystal has been used for a long time. For example, as disclosed inJP-A-2014-86842, the resonation device, which cantilever-supports theresonator element on a connection pad in a container by using anelectroconductive adhesive, is configured to stably secure a thicknessof the electroconductive adhesive by providing a bank portion on anelectrode pad in the container. In such a configuration, the resonationdevice reduces a temperature gradient in the resonator element byreducing heat from being transferred to the resonator element from theoutside of the container via an electroconductive adhesive so as toreduce the variation in frequency characteristics of the resonationdevice, for example, reproducibility of a frequency change with respectto a temperature change, that is, a hysteresis.

However, in the resonation device disclosed in JP-A-2014-86842, thehysteresis which is the variation in frequency characteristics of theresonation device is also changed due to a stress which is caused by anambient temperature change of the resonation device and is applied tothe resonator element, other than the heat transferred from the outsideof the container. The stress which is caused by the ambient temperaturechange of the resonation device and is applied to the resonator elementgreatly affects a positional relationship between a distance betweenconnection members which connect the resonator element and the containerand an excitation electrode of the resonator element. For this reason,it is likely that the variation in characteristics of the resonationdevice, for example, the hysteresis is increased by when only securingthe stable thickness of the electroconductive adhesive which connectsthe container and the resonator element as the resonation devicedisclosed in JP-A-2014-86842.

SUMMARY

An advantage of some aspects of the invention is to solve at least apart of the problems described above, and the invention can beimplemented as the following forms or application examples.

Application Example 1

A resonation device according to this application example includes asubstrate; a resonator element which includes a resonation areainterposed between a pair of excitation electrodes which are disposed ona front surface and a rear surface; and a first bonding member and asecond bonding member which bond the resonator element and thesubstrate, and are disposed side by side in a first direction along thefirst side of the resonator element, in which the excitation electrodeincludes a base layer including at least one type of metal of nickel andtungsten on the front and rear surface, and an upper layer including atleast one type of metal among gold, platinum, silver, aluminum, andcopper on the base layer, the center of a resonator element-side surfaceof the first bonding member is set to be a first bonding center, thecenter of a resonator element-side surface of the second bonding memberis set to be a second bonding center, and a center which is viewed fromone side of the pair of excitation electrodes in the resonation area isset to be a resonation area center, and when a distance between thefirst bonding center and the second bonding center is set to be L1, anda length of a perpendicular line drawn to a virtual line which connectsthe first bonding center and the second bonding center from theresonation area center is set to be L2, a relationship expressed by0<L1/L2≦0.97 is satisfied.

According to this application example, in a case where the stress isgenerated due to a difference between an elongation amount or ashrinkage amount of the resonator element and an elongation amount or ashrinkage amount of the substrate, in accordance with the change of theambient temperature of the resonation device, it is possible to reducethe stress, which is generated due to the difference between theelongation amount or the shrinkage amount of the resonator element andthe elongation amount or the shrinkage amount of the substrate, so asnot to be transferred to the resonation area of the resonator element bysatisfying a relationship expressed by 0<L1/L2≦0.97. The characteristicsof the resonator element, for example, an output frequency, afrequency-temperature characteristic, and an equivalent seriesresistance are greatly varied depending on a state of the resonationarea, and thus when the stress transferred to the resonation area isreduced, and thus it is possible to reduce the variation incharacteristics of the resonation device, for example, the variation inthe frequency-temperature characteristic or the hysteresis.

Application Example 2

In the resonation device according to the application example, it ispreferable that a relationship expressed by 0<L1/L2≦0.85 is satisfied.

According to this application example, for example, in a case where thestress is generated due to the difference between the elongation amountor the shrinkage amount of the resonator element and the elongationamount or the shrinkage amount of the substrate, in accordance with thechange of the ambient temperature of the resonation device, it ispossible to further reduce the stress, which is generated due to thedifference between the elongation amount or the shrinkage amount of theresonator element and the elongation amount or the shrinkage amount ofthe substrate, so as not to be transferred to the resonation area of theresonator element by satisfying a relationship expressed by0<L1/L2≦0.85. Accordingly, when the stress transferred to the resonationarea of the resonator element is reduced, it is possible to furtherreduce the variation in characteristics of the resonation device, forexample, the hysteresis compared with Application Example 1.

Application Example 3

In the resonation device according to the application example, it ispreferable that when a virtual line which passes through the resonationarea center and is parallel to the first direction is set to be a thirdvirtual line, a distance between the first bonding center and theperpendicular line is set to be La, a distance between the secondbonding center and the perpendicular line is set to be Lb, a distancebetween the resonation area center and an end portion of the resonationarea, which is positioned on the first bonding member side with respectto the perpendicular line and intersects with the third virtual line, isset to be Wa, and a distance between the resonation area center and anend portion of the resonation area, which is positioned on the secondbonding member side with respect to the perpendicular line andintersects with the third virtual line, is set to be Wb, in case ofLa/Wa>Lb/Wb, relationship expressed by 0<La/Wa≦0.89 is satisfied, and incase of La/Wa<Lb/Wb, relationship expressed by 0<Lb/Wb≦0.89 issatisfied.

According to this application example, in a case where the stress isgenerated due to the difference between the elongation amount or theshrinkage amount of the resonator element and the elongation amount orthe shrinkage amount of the substrate, in accordance with the change ofthe ambient temperature of the resonation device, it is possible toreduce the stress, which is generated due to the difference between theelongation amount or the shrinkage amount of the resonator element andthe elongation amount or the shrinkage amount of the substrate, so asnot to be transferred to the resonation area of the resonator element byrespectively satisfying the relationships expressed by 0<La/Wa≦0.89 and0<Lb/Wb≦0.89 in the cases of La/Wa>Lb/Wb and La/Wa<Lb/Wb. Thecharacteristics of the resonator element, for example, the outputfrequency, the frequency-temperature characteristic, and the equivalentseries resistance are greatly varied depending on the state of theresonation area, and thus when the stress transferred to the resonationarea is reduced, and thus it is possible to reduce the variation incharacteristics of the resonation device, for example, the variation inthe frequency-temperature characteristic or the hysteresis.

Application Example 4

In the resonation device according to the application example, it ispreferable that in case of La/Wa>Lb/Wb, relationship expressed by0<La/Wa≦0.77 is satisfied, and in case of La/Wa<Lb/Wb, relationshipexpressed by 0<Lb/Wb≦0.77 is satisfied.

According to this application example, for example, in a case where thestress is generated due to the difference between the elongation amountor the shrinkage amount of the resonator element and the elongationamount or the shrinkage amount of the substrate, in accordance with thechange of the ambient temperature of the resonation device, it ispossible to further reduce the stress, which is generated due to thedifference between the elongation amount or the shrinkage amount of theresonator element and the elongation amount or the shrinkage amount ofthe substrate, so as not to be transferred to the resonation area of theresonator element by respectively satisfying the relationships expressedby 0<L1/W1≦0.77 and 0<L2/W2≦0.77 in the cases of L1/W1>L2/W2 andL1/W1<L2/W2. Accordingly, when the stress transferred to the resonationarea of the resonator element is further reduced, it is possible toreduce the variation in characteristics of the resonation device, forexample, the hysteresis by 28% or more than that in Application Example3.

Application Example 5

In the resonation device according to the application example, it ispreferable that in a planar view, the resonator element includes ahollow between the virtual line which connects the first bonding centerand the second bonding center, and the excitation electrode in adirection in which at least one surface of the front surface and therear surface faces the other surface.

According to this application example, the stress, which is generateddue to the difference between the elongation amount or the shrinkageamount of the resonator element and the elongation amount or theshrinkage amount of the substrate in accordance with the change of theambient temperature of the resonation device, is also transferred to theresonation area via a hollow, and a length of a portion in which thehollow is formed is shorter than that of a portion in which the hollowis not formed in the direction intersecting with the front surface andthe rear surface, that is, the portion in which the hollow is formed isthin, and thus is easily distorted. Accordingly, the stress, which isgenerated due to the difference between the elongation amount or theshrinkage amount of the resonator element and the elongation amount orthe shrinkage amount of the substrate in accordance with the change ofthe ambient temperature of the resonation device, is absorbed becausethe portion in which the hollow is formed is much more distorted thanthe portion in which the hollow is not formed, and thus when the stresstransferred to the resonation area of the resonator element is reduced,it is possible to further reduce the variation in characteristics of theresonation device, for example, the variation in thefrequency-temperature characteristic, or the hysteresis.

Application Example 6

In the resonation device according to the application example, it ispreferable that the hollow is a hole which penetrates from one surfaceof the front surface and the rear surface to the other surface.

According to this application example, the stress, which is generateddue to the difference between the elongation amount or the shrinkageamount of the resonator element and the elongation amount or theshrinkage amount of the substrate in accordance with the change of theambient temperature of the resonation device, is transferred to theresonation area via an area in which the hole is not opened and an areaadjacent to an area in which the hole is opened of the resonatorelement, and the area adjacent to the area in which the hole is openedof the resonator element is more easily distorted than the area which isnot adjacent to the area in which the hole is opened, that is, the areain which the hole is not opened. Accordingly, the stress, which isgenerated due to the difference between the elongation amount or theshrinkage amount of the resonator element and the elongation amount orthe shrinkage amount of the substrate in accordance with the change ofthe ambient temperature of the resonation device, is absorbed becausethe area adjacent to the area in which the hole is opened of theresonator element is much more distorted than the area in which the holeis not opened, and thus when the stress transferred to the resonationarea of the resonator element is reduced, it is possible to furtherreduce the variation in characteristics of the resonation device, forexample, the variation in the frequency-temperature characteristic, orthe hysteresis.

Application Example 7

In the resonation device according to the application example, it ispreferable that the resonator element includes a first area having afirst thickness and a second area having a thickness which is smallerthan the first thickness in the direction which intersects with thefront surface and the rear surface, in which the resonation area centeroverlaps the first area in a planar view, and the first bonding centerand the second bonding center overlaps the second area in planar view.

According to this application example, the stress, which is generateddue to the difference between the elongation amount or the shrinkageamount of the resonator element and the elongation amount or theshrinkage amount of the substrate in accordance with the change of theambient temperature of the resonation device, is transferred to theresonation area via second area, and the second area is thinner than thefirst area and thus is more easily distorted. Accordingly, the stress,which is generated due to the difference between the elongation amountor the shrinkage amount of the resonator element and the elongationamount or the shrinkage amount of the substrate in accordance with thechange of the ambient temperature of the resonation device, is absorbedbecause the second area is much more distorted than the first area, andthus when the stress transferred to the resonation area of the resonatorelement is further reduced, it is possible to further reduce thevariation in characteristics of the resonation device, for example, thevariation in the frequency-temperature characteristic, or thehysteresis.

Application Example 8

In the resonation device according to the application example, it ispreferable that the first bonding member and the second bonding memberhave conductivity.

According to this application example, the first bonding member and thesecond bonding member have the conductivity, and thus a mechanicalbonding and an electrical bonding can be concurrently performed betweenthe resonator element and the substrate. Accordingly, it is possible toreduce the number of members used for the resonation device comparedwith a case where the mechanical bonding and the electrical bondingwhich are performed between the resonator element and the substrate byusing different members, and thus it is possible to efficientlymanufacture the resonation device in which the variation in thefrequency-temperature characteristic, the hysteresis, or the like isreduced.

Application Example 9

In the resonation device according to the application example, it ispreferable that at least one of the first bonding member and the secondbonding member is formed of a metallic bump.

According to this application example, at least one of the first bondingmember and the second bonding member is formed of the metallic bump, forexample, metal which is formed through a plating method and a bondingmethod. The metallic bump has less gas emission from the inside of themetallic bump due to the heat and the time elapse compared with a resinmember such as an adhesive. Accordingly, it is possible to reduce thevariation in characteristics of the resonation device, for example, thevariation in the frequency-temperature characteristic or the hysteresis,and to reduce the variation of the characteristics of the resonationdevice, for example, the output frequency, the frequency-temperaturecharacteristic, and the equivalent series resistance due to the heat andthe time elapse of the resonation device.

Application Example 10, Application Example 11, Application Example 12,and Application Example 13

An oscillator according to each of these application examples includesthe resonation device according to any one of the above-describedapplication examples, which is bonded to the substrate and has a lidwhich forms an inner space for accommodating the resonator element; anoscillation circuit which is connected to one surface of the resonationdevice via a bonding member; and a container which accommodates theresonation device and the oscillation circuit.

According to these application examples, it is possible to realize theoscillator having high reliability in which the variation incharacteristics is reduced, for example, the variation in thefrequency-temperature characteristic or the hysteresis is reduced byusing the resonation device which reduces the variation incharacteristics by reducing the stress which is generated due to adifference between an elongation amount or a shrinkage amount of theresonator element and an elongation amount or a shrinkage amount of thesubstrate in accordance with the change of the ambient temperature ofthe resonation device, so as not to be transferred to the resonatorelement.

Application Example 14, Application Example 15, Application Example 16,and Application Example 17

In the oscillator according to the application examples, the lid and theoscillation circuit may be connected to each other via bonding member inthe oscillator according to any one of the above-described applicationexamples.

According to these application examples, it is possible to realize theoscillator having high reliability in which the variation incharacteristics, for example, the variation in the frequency-temperaturecharacteristic or the hysteresis is reduced by using the resonationdevice which reduces the variation in characteristics by reducing thestress which is generated due to a difference between an elongationamount or a shrinkage amount of the resonator element and an elongationamount or a shrinkage amount of the substrate in accordance with thechange of the ambient temperature of the resonation device, so as not tobe transferred to the resonator element.

Application Example 18

An electronic apparatus according to this application example includesthe resonation device according to any one of the above-describedapplication examples.

According to this application example, it is possible to realize theelectronic apparatus having high reliability in which the variation incharacteristics, for example, the variation in the frequency-temperaturecharacteristic or the hysteresis is reduced by using the resonationdevice which reduces the variation in characteristics by reducing thestress which is generated due to a difference between an elongationamount or a shrinkage amount of the resonator element and an elongationamount or a shrinkage amount of the substrate in accordance with thechange of the ambient temperature of the resonation device, so as not tobe transferred to the resonator element.

Application Example 19

A moving object according to this application example includes theresonation device according to any one of the above-describedapplication examples.

According to this application example, it is possible to realize themoving object having high reliability in which the variation incharacteristics, for example, the variation in the frequency-temperaturecharacteristic or the hysteresis is reduced by using the resonationdevice which reduces the variation in characteristics by reducing thestress which is generated due to a difference between an elongationamount or a shrinkage amount of the resonator element and an elongationamount or a shrinkage amount of the substrate in accordance with thechange of the ambient temperature of the resonation device, so as not tobe transferred to the resonator element.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIGS. 1A and 1B are schematic configuration diagrams of a crystalresonator 100 as a resonation device according to a first embodiment,and FIG. 1A is a plan view and FIG. 1B is a sectional view taken alongline A-A of FIG. 1A.

FIGS. 2A and 2B are diagrams illustrating deflection of the resonatorelement according to the first embodiment, and FIG. 2A is a sectionalview taken along a first virtual line when a relationship expressed byL1=W1 is satisfied in FIG. 1A, and FIG. 2B is a sectional view takenalong the first virtual line when a relationship expressed by L1=W2 issatisfied in FIG. 1A.

FIGS. 3A and 3B are diagrams illustrating a stress applied to theresonator element according to the first embodiment, and FIG. 3A is asectional view taken along a second virtual line in FIG. 1A, and FIG. 3Bis a schematic view of a stress distribution when relationshipsexpressed by L1=W1 and L1=W2 are satisfied.

FIG. 4 is a diagram illustrating a relationship between L1/L2 and ahysteresis of a frequency-temperature characteristic of the crystalresonator.

FIGS. 5A and 5B are schematic configuration diagrams of a crystalresonator 200 as a resonation device according to a second embodiment,and FIG. 5A is a plan view and FIG. 5B is a sectional view taken alongline B-B of FIG. 5A.

FIGS. 6A and 6B are schematic configuration diagrams of a crystalresonator 300 as a resonation device according to a third embodiment,and FIG. 6A is a plan view and FIG. 6B is a sectional view taken alongline C-C of FIG. 6A.

FIGS. 7A and 7C are schematic configuration diagrams of a crystalresonator 400 as a resonation device according to a fourth embodiment,and FIG. 7A is a plan view, FIG. 7B is a sectional view taken along lineD-D of FIG. 7A, and FIG. 7C is a sectional view of a part of anexcitation electrode portion.

FIGS. 8A and 8E are schematic configuration diagrams illustratingModification Example of the resonator element of the crystal resonator400 as the resonation device according to the fourth embodiment, andFIG. 8A is a plan view of the resonator element 410 which is an exampleof Modification Example, FIG. 8B is a sectional view taken along lineE-E in FIG. 8A, FIG. 8C is a plan view of the resonator element 510which is another example of Modification Example, FIG. 8D is a sectionalview taken along line F-F in FIG. 8C, and FIG. 8E is a partiallyenlarged sectional view of an excitation electrode portion in FIG. 8D.

FIGS. 9A and 9B are schematic configuration diagrams of a crystalresonator 500 as a resonation device according to a fifth embodiment,and FIG. 9A is a plan view and FIG. 9B is a sectional view taken alongline G-G of FIG. 9A.

FIGS. 10A and 10B are schematic configuration diagrams of a crystalresonator 600 as a resonation device according to a sixth embodiment,and FIG. 10A is a plan view and FIG. 10B is a sectional view taken alongline H-H of FIG. 10A.

FIG. 11 is a diagram illustrating a relationship between Lb/Wb and ahysteresis of the crystal resonator 600.

FIGS. 12A and 12B are schematic configuration diagrams of an oscillatorresonator according to a seventh embodiment, and FIG. 12A is a plan viewand FIG. 12B is a sectional view taken along line J-J of FIG. 12A.

FIG. 13 is a perspective view illustrating a configuration of amobile-type (or a note book-type) personal computer as an electronicapparatus according to an eighth embodiment.

FIG. 14 is a perspective view illustrating a mobile phone as theelectronic apparatus according to the eighth embodiment.

FIG. 15 is a perspective view illustrating a digital camera as theelectronic apparatus according to the eighth embodiment.

FIG. 16 is a perspective view illustrating an automobile as a movingobject according to a ninth embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Hereinafter, the embodiment of the invention will be described withreference to the drawings. Further, in the following drawings, in orderto make the magnitude of the respective layers and members recognizable,there is a case of making the scale of the respective layers and membersdifferent from that in the actual structure.

First Embodiment

A crystal resonator 100 as an example of a resonation device accordingto the embodiment will be described. The crystal resonator 100 is aresonation device which oscillates at a predetermined frequency by apredetermined AC voltage applied from the outside.

Crystal Resonator

First, a schematic configuration of the crystal resonator 100 as theresonation device according to the first embodiment will be described.FIGS. 1A and 1B are schematic configuration diagrams of the crystalresonator 100 as the resonation device of the first embodiment, and FIG.1A is a plan view and FIG. 1B is a sectional view taken along line A-Aof FIG. 1A.

The crystal resonator 100 is provided with a resonator element 10, apackage 20, a first bonding member 41, a second bonding member 42, a lid(a lid body) 30, and the like. Note that, for the sake of convenience ofdescription, the lid 30 is not shown in FIG. 1A. In addition, in thefollowing description, an upper side in FIG. 1B is referred to as “up”and a lower side is referred to as “down”, and a surface on the upperside of each member in FIG. 1B is referred to as an upper surface, and asurface on the lower side is referred to as a lower surface.

Resonator Element

The resonator element 10 is provided with a crystal substrate 11 formedof a crystal which is a type of piezoelectric single crystal, excitationelectrodes 12 a and 13 a, extracting electrodes 12 b and 13 b, andconnection electrodes 12 c and 13 c. The resonator element 10 resonatesat a predetermined resonance frequency by applying a predetermined ACvoltage to the excitation electrodes 12 a and 13 a.

The crystal substrate 11 includes an upper surface 11 a and a lowersurface 11 b which are respectively the front surface and the rearsurface, and a first side 11 e. The excitation electrode 12 a and theextracting electrode 12 b are formed on the upper surface 11 a of thecrystal substrate 11. The excitation electrode 13 a, the extractingelectrode 13 b, and the connection electrodes 12 c and 13 c are formedon the lower surface 11 b of the crystal substrate 11. In addition, theconnection electrodes 12 c and 13 c are arranged close to the first side11 e of the lower surface 11 b of the crystal substrate 11 in the firstdirection 54. The extracting electrode 12 b extends from the excitationelectrode 12 a to the connection electrode 12 c via side surface whichconnects the upper surface 11 a and the lower surface 11 b, andelectrically connects the excitation electrode 12 a and the connectionelectrode 12 c. The extracting electrode 13 b extends from theexcitation electrode 13 a to the connection electrode 13 c, andelectrically connects the excitation electrode 13 a and the connectionelectrode 13 c.

The excitation electrodes 12 a and 13 a are formed into a rectangularshape in a planar view, that is, when viewed from above, and aredisposed so as to substantially overlap with each other in such a mannerthat the center of the excitation electrode 12 a and the center of theexcitation electrode 13 a substantially overlap with each other. Inaddition, the crystal substrate 11 includes a resonation area 11 c whichis interposed between the excitation electrodes 12 a and 13 a. Here, thecenter of each of the excitation electrodes 12 a and 13 a is thecentroid (the center of a drawing) of the shape when the respectiveexcitation electrodes 12 a and 13 a are viewed from above.

In the embodiment, the excitation electrodes 12 a and 13 a are disposedin such a manner that the center of the excitation electrode 12 a andthe center of the excitation electrode 13 a substantially overlap witheach other; however, it is not limited thereto as long as the excitationelectrode 12 a and the excitation electrode 13 a overlap with each otherwhen viewed from above and have the resonation area 11 c. In addition,the excitation electrodes 12 a and 13 a may be formed into a polygonalshape such as a circular shape, an elliptical shape, and a triangularshape, or may be formed into a polygonal shape having a rounded corner,in addition to the rectangular shape.

The excitation electrodes 12 a and 13 a, the extracting electrodes 12 band 13 b, and the connection electrodes 12 c and 13 c are formed througha method such as a vapor deposition method, a sputtering method, and aplating method, or through a method of volatilizing a solvent componentother than metal after performing the coating with a paste (a solvent)including a metallic member. In addition, the excitation electrodes 12 aand 13 a, the extracting electrodes 12 b and 13 b, and the connectionelectrodes 12 c and 13 c are configured to have at least two layers of abase layer and an upper layer. Examples of a configuration material forthe base layer include an adhesion material with respect to the crystalsubstrate 11, and specifically, a metallic element such as chromium(Cr), nickel (Ni), titanium (Ti), and tungsten (W), a mixture includingone or two or more the metallic elements, or an alloy can be used. Onthe other hand, examples of a material for the upper layer include aconfiguration material having particularly high electrical conductionproperties, and specifically, a metallic element such as gold (Au),platinum (Pt), silver (Ag), aluminum (Al), and copper (Cu), a mixtureincluding one or two or more the metallic elements, or an alloy can beused. Note that, the excitation electrodes 12 a and 13 a, the extractingelectrodes 12 b and 13 b, and the connection electrodes 12 c and 13 cmay be configured to have one layer, for example, may be configured tohave a metallic element such as gold (Au), platinum (Pt), silver (Ag),aluminum (Al), and copper (Cu), a mixture including one or two or morethe metallic elements, or an alloy.

The resonation area 11 c includes a resonation area center 11 d. In theembodiment, the excitation electrodes 12 a and 13 a are formed into arectangular shape and are disposed so as to substantially overlap witheach other when viewed from above, and thus the resonation area 11 c isformed into a rectangular shape and the resonation area center 11 d andthe center of each of the excitation electrodes 12 a and 13 asubstantially overlap with each other when viewed from above. Here, theresonation area center 11 d is the centroid (the center of a drawing) ofthe shape when the resonation area 11 c is viewed from above.

Package

The package 20 is provided with a bottom plate 21 as a substrate, a sidewall 22, a seal ring 23, and the like, and the bottom plate 21 includesan upper surface 21 a and a lower surface 21 b.

Specifically, in the package 20, an inner space 26 (an accommodatingspace) of which the center portion is depressed by stacking the sidewall 22 on a peripheral portion of the upper surface 21 a on the bottomplate 21, and the resonator element 10 is accommodated in the innerspace 26. The outer shape of the package 20 is not limited, for example,it may be a rectangular parallelepiped shape, a cylindrical shape, orthe like.

The bottom plate 21 and the side wall 22 are preferably formed of amaterial having the same or approximate coefficient of thermal expansionas that of the resonator element 10 and the lid 30, and ceramics areused in the embodiment.

The seal ring 23 serves as a bonding material which bonds the side wall22 and the lid 30, is formed of, for example, a metallic brazingmaterial such as a gold brazing material and a silver brazing material,or metal such as glass or kovar, and is provided in a frame shape alongthe upper surface of the side wall 22.

In addition, the internal connection terminals 24 a and 24 b are formedon the upper surface 21 a of the bottom plate 21, and a plurality ofexternal connection terminals 25 which are electrically connected to atleast an outer circuit and a mount substrate of the crystal resonator100 are formed on the lower surface 21 b of the bottom plate 21.

The internal connection terminals 24 a and 24 b and the plurality ofexternal connection terminals 25 are obtained through sequential stepsof, for example, tungsten metalizing, nickel-plating, and gold-plating.

The internal connection terminals 24 a and 24 b are electricallyconnected to two external connection terminals 25 which are differentfrom each other in the plurality of external connection terminals 25 viaa wiring (not shown) which is disposed on the bottom plate 21. Inaddition, the plurality of external connection terminals 25 areelectrodes which are used to supply an AC voltage to the resonatorelement 10 and output an electrical signal such as a frequency by beingelectrically connected to at least the external mount substrate (notshown).

Lid

The lid 30 is formed into a flat plate-like shape which covers anopening of the package 20, and formed of metal such as kovar and 42alloy, ceramics, glass and the like.

The lid 30 is bonded to the seal ring 23 such that the inner space 26 isin an air-tight state, after the resonator element 10 is accommodated inthe inner space 26 of the package 20. An inner pressure of the innerspace 26 which is in the air-tight state is set to be a predeterminedpressure. For example, when the inner space 26 is in a vacuum state (astate where a pressure is lower than an atmospheric pressure (1×10⁵ Pato 1×10⁻¹⁰ Pa (JIS Z 8126-1: 1999))) or in the same pressure state asthe atmospheric pressure by being filled with an inert gas such asnitrogen or argon. Therefore, the resonator element 10 can continuouslyand stably resonate.

In addition, the inner space 26 in the embodiment is tightly sealed in avacuum state. When the inner space 26 is tightly sealed in the vacuumstate, a Q value of the accommodated resonator element 10 is increased,and thus the resonator element 10 can continuously and stably resonate.

Bonding Member

The first bonding member 41 and the second bonding member 42 arearranged in the direction in which the first side 11 e of the lowersurface 11 b on the crystal substrate 11 extends.

The first bonding member 41 and the second bonding member 42 are formedof a resin containing a conductive member, for example, anelectroconductive adhesive. Examples of the conductive member include ametallic element such as gold (Au), silver (Ag), copper (Cu), aluminum(Al), and platinum (Pt), a mixture such as a metallic fine particleincluding one or two or more the metallic elements, a resin fineparticle obtained by plating the aforementioned metallic elements, and acarbon fine particle. Examples of the resin include an epoxy-basedresin, a silicon-based resin, a polyimide-based resin, a polyamide-basedresin, or an acrylic resin.

The first bonding member 41 is electrically and mechanically connectedto the connection electrode 12 c, and is electrically and mechanicallyconnected to an internal connection terminal 24 a. The second bondingmember 42 is electrically and mechanically connected to the connectionelectrode 13 c, and is electrically and mechanically connected to aninternal connection terminal 24 b. In other words, the resonator element10 is supported by the bottom plate 21 via the first bonding member 41and the internal connection terminal 24 a, and the second bonding member42 and the internal connection terminal 24 b. That is, when viewed fromabove, the resonator element 10 does not come in contact with the bottomplate 21, the side wall 22, the seal ring 23, and the lid 30 but iscantilever-supported by the bottom plate 21 in an area close to a sidethat the first side 11 e faces with the excitation electrodes 12 a and13 a interposed therebetween.

Since the first bonding member 41 and the second bonding member 42 haveconductivity, a mechanical bonding and an electrical bonding can beconcurrently performed between the connection electrode 12 c and theinternal connection terminal 24 a, and between the connection electrode13 c and the internal connection terminal 24 b. Accordingly, it ispossible to reduce the number of members used for the resonation devicecompared with a case where the mechanical bonding and the electricalbonding which are performed between the resonator element 10 and thebottom plate 21 by using different members, and thus it is possible toefficiently manufacture the crystal resonator 100.

A first bonding center 41 b is positioned on the connection electrode 12c side of the first bonding member 41, that is, an upper surface 41 a onthe resonator element 10 side. A second bonding center 42 b ispositioned on the connection electrode 13 c side of the second bondingmember 42, that is, an upper surface 42 a on the resonator element 10side.

Each of the first bonding center 41 b and the second bonding center 42 bhas a shape when the first bonding member 41 and the second bondingmember 42 are viewed from above, that is, the centroid (the center of adrawing) of the shape when the upper surface 41 a and the upper surface42 a are viewed from above.

Next, a relationship between the resonation area 11 c, the first bondingmember 41, and the second bonding member 42 will be described.

First, a virtual line which passes through the first bonding center 41 band the second bonding center 42 b is set to be a first virtual line 51,a virtual line which passes through the resonation area center 11 d andperpendicular to a first virtual line 51 is set to be a second virtualline 52. In addition, an intersection 53 of the first virtual line 51and the second virtual line 52 is disposed between the first bondingcenter 41 b and the second bonding center 42 b. That is, the firstbonding member 41 and the second bonding member 42 are arranged in thefirst direction 54 which is the direction in which the first side 11 eextends while interposing the second virtual line 52 therebetween whenviewed from above.

Here, when a distance between the first bonding center 41 b and thesecond bonding center 42 b is set to be L1, and a length ofperpendicular line drawn to a virtual line which connects the firstbonding center 41 b and a second bonding center 42 b from the resonationarea center 11 d is set to be L2, that is, a distance between theresonation area center 11 d and the intersection 53 is set to be L2, arelationship between the aforementioned L1 and L2 and a hysteresis willbe described below.

First, the hysteresis of the crystal resonator 100 will be described.Regarding a resonance frequency of the resonator element 10, a resonancefrequency at a predetermined temperature T in a process in which anambient temperature of the crystal resonator 100 is increased, and aresonance frequency at a predetermined temperature T in a process inwhich an ambient temperature of the crystal resonator 100 is decreasedhave different characteristics from each other. Having differentcharacteristics depending on the time the ambient temperature isincreased or decreased means to have the hysteresis. The reason for thisis as follows.

Since the crystal resonator 100 according to the embodiment is formed ofa different material from that of the resonator element 10 and thebottom plate 21, it has a different coefficient of thermal expansion,and thus an elongation amount or a shrinkage amount of the resonatorelement 10, and an elongation amount or a shrinkage amount the bottomplate 21 in accordance with a change of the ambient temperature of thecrystal resonator 100 are different from each other. Accordingly, whenthe ambient temperature of the crystal resonator 100 is changed, astress is generated in the resonator element 10 due to a differencebetween the elongation amount or the shrinkage amount of the resonatorelement 10 and the elongation amount or the shrinkage amount of thebottom plate 21.

In addition, when the resonator element 10 is bonded to the inside ofthe crystal resonator 100, that is, the inside of the package 20 via thefirst bonding member 41 and the second bonding member 42, the change ofthe ambient temperature of the crystal resonator 100 is slowlytransferred to the resonator element 10 compared with the bottom plate21. That is, in the process in which the ambient temperature of thecrystal resonator 100 is increased, the temperature of the resonatorelement 10 is lower than a predetermined temperature T even when theambient temperature of the crystal resonator 100 becomes a predeterminedtemperature T, and in the process in which the ambient temperature ofthe crystal resonator 100 is decreased, the temperature of the resonatorelement 10 is higher than a predetermined temperature T even when theambient temperature of the crystal resonator 100 becomes a predeterminedtemperature T.

From the above description, even when the ambient temperature of thecrystal resonator 100 is a predetermined temperature T, the temperatureof the resonator element 10 is differentiated depending on the processin which the ambient temperature is increased or the process in whichthe ambient temperature is decreased, and thus the elongation amount orthe shrinkage amount of the resonator element 10 is differentiated.Accordingly, the stress is generated in the resonator element 10 due tothe difference between the elongation amount or the shrinkage amount ofthe resonator element 10 and the elongation amount or the shrinkageamount of the bottom plate 21, and the stress generated in a case wherethe ambient temperature becomes a predetermined temperature T in theprocess in which the ambient temperature of the crystal resonator 100 isincreased is different from the stress generated in a case where theambient temperature becomes a predetermined temperature T in the processin which the ambient temperature is decreased.

Further, it is known that the resonance frequency of the resonatorelement 10 when a predetermined AC voltage is applied to the resonatorelement 10 is changed due to a stress applied to the resonator element10.

Accordingly, regarding the resonance frequency of the crystal resonator100 including the resonator element 10, the resonance frequency at thetemperature T in the process in which the ambient temperature of thecrystal resonator 100 is increased is different from the resonancefrequency at the temperature T in the process in which the ambienttemperature of the crystal resonator 100 is decreased, and thisphenomenon is called a characteristic of the hysteresis or thehysteresis.

The reason why the resonance frequency of the resonator element 10 ischanged when the stress is applied to the resonator element 10 is thatthe stress is also applied to the resonation area 11 c in which a largeamount of resonation energy is concentrated in a state where theresonator element 10 resonates, and then the distribution of theresonation energy in the resonation area 11 c is changed. In addition,in a case where the stress is applied to the entire resonation area 11c, that is, as a range of the area to which the stress is applied isspread in the resonation area 11 c, the distribution of the resonationenergy in the resonation area 11 c is affected compared with a casewhere the stress is applied to a portion in the resonation area 11 c,and therefore, it is considered that an amount of change in theresonance frequency of the resonator element 10 becomes larger. Fromabove description, it is considered that when reducing the stress, whichis generated by the difference between the elongation amount or theshrinkage amount of the resonator element 10 and the elongation amountor the shrinkage amount of the bottom plate 21 in accordance with thechange of the ambient temperature of the crystal resonator 100, so asnot to be transferred to the resonation area 11 c, it is possible toreduce the change of the resonance frequency of the resonator element10.

In this regard, the inventors of the present application have studiedregarding a relationship between the resonation area 11 c, the firstbonding member 41 and the second bonding member 42, and the stressdistribution in the resonator element 10.

FIGS. 2A and 2B and FIGS. 3A and 3B are diagrams illustrating the stressapplied to the resonator element 10 when the ambient temperature becomesa predetermined temperature T in the process in which the ambienttemperature of the crystal resonator is increased or decreased. FIG. 2Ais a diagram illustrating a deflection of the resonator element 10 whenviewed from a sectional direction along the first virtual line 51 in acase where the ambient temperature becomes a predetermined temperature Tin the process in which the ambient temperature of the crystal resonator100 a is decreased in a crystal resonator 100 a which satisfies arelationship expressed by L1=W1 in FIGS. 1A and 1B, and FIG. 2B is adiagram illustrating a deflection of the resonator element 10 whenviewed from a sectional direction along the first virtual line in a casewhere the ambient temperature becomes a predetermined temperature T inthe process in which the ambient temperature of the crystal resonator100 b is decreased in the crystal resonator 100 b which satisfies arelationship expressed by L1=W2 in FIGS. 1A and 1B. Note that, W1 and W2satisfy a relationship expressed by W1>W2. In addition, the crystalresonator 100 a and the crystal resonator 100 b have the same distanceL2 between the intersection 53 and the resonation area center 11 d.

FIG. 3A is a sectional view along the second virtual line 52 in FIG. 1A.FIG. 3B is a schematic view illustrating the stress distribution in theresonator element 10 in the direction in which the second virtual line52 extends when the ambient temperature becomes a predeterminedtemperature T, in the crystal resonator 100 a in FIG. 2A and the crystalresonator 100 b in FIG. 2B, and Sa represents the stress distribution inthe resonator element 10 in the crystal resonator 100 a and Sbrepresents the stress distribution in the resonator element 10 in thecrystal resonator 100 b. In addition, in FIG. 3B, a vertical axisrepresents an absolute value of the stress S [N/m²], and a horizontalaxis represents a distance D [mm] from the intersection 53. In addition,in FIGS. 3A and 3B, a distance between the intersection 53 and an endportion 55, which is close to the first virtual line 51 side withrespect to the resonation area center 11 d, in the resonation area 11 cis set to be d1, a distance between the first virtual line 51 and theresonation area center 11 d is set to be d2, and a distance between theintersection 53 and an end portion 56, which is close to the sideopposite to the first virtual line 51 with respect to the resonationarea center 11 d, in the resonation area 11 c is set to be d3.

Note that, for the sake of convenience of description, the side wall 22,the seal ring 23, and the external connection terminal 25 are notillustrated in FIGS. 2A and 2B, and FIG. 3A. In addition, in each of thecrystal resonators 100 a and 100 b, the excitation electrodes 12 a and13 a are disposed in the same way in the resonator element 10.

As described in the above-mentioned hysteresis, the ambient temperaturesof the crystal resonators 100 a and 100 b are changed, a difference inthe temperature between the resonator element 10 and the bottom plate 21occurs due to a difference in heat transmission. For example, when theambient temperature becomes a predetermined temperature T in the processin which the ambient temperatures of the crystal resonators 100 a and100 b are decreased, even when the temperature of the bottom plate 21becomes a predetermined temperature T, the temperature of the resonatorelement 10 is higher than a predetermined temperature T. For thisreason, for example, in a case where the resonator element 10 and thebottom plate 21 have the same value of positive coefficient of thermalexpansion, the temperature of the resonator element 10 is higher thanthe temperature of the bottom plate 21 in a predetermined temperature T,and thus the elongation amount of the resonator element 10 is largerthan elongation amount of the bottom plate 21. Therefore, the resonatorelement 10 is deflected in the thickness direction.

FIGS. 2A and 2B illustrate the deflection of the resonator element 10when the ambient temperature becomes a predetermined temperature T inthe process in which the ambient temperatures of the crystal resonators100 a and 100 b are decreased. From FIGS. 2A and 2B, it is found thatregarding the deflection occurred in the resonator element 10,deflection δ2 occurred in the crystal resonator 100 b which satisfiesthe relationship expressed by L1=W2 in FIG. 2B is smaller thandeflection 61 occurred in the crystal resonator 100 a which satisfiesthe relationship expressed by L1=W1 in FIG. 2A. The reason for this isthat regarding the distance L1 between the first bonding center 41 b andthe second bonding center 42 b, which is an interval of the bondingmember supporting the resonator element 10, the distance W2 in thecrystal resonator 100 b is shorter than the distance W1 in the crystalresonator 100 a, and thus the absolute value of the difference betweenthe elongation amount or the shrinkage amount of the resonator element10 and the elongation amount or the shrinkage amount of the bottom plate21 is reduced.

FIG. 3B is a schematic view illustrating the distribution of the stressgenerated in the resonator element 10 due to the deflection illustratedin FIGS. 2A and 2B, in the direction in which the second virtual line 52extends in a sectional portion of FIG. 3A. From FIG. 3B, it is foundthat regarding the distribution of the stress generated in the resonatorelement 10, Sa and Sb become the maximum values when satisfying arelationship expressed by D=0, and the respective values thereof are Sa0and Sb0. In addition, the stress applied to each of Sa and Sb is reducedas the distance D from the intersection 53 becomes longer.

Further, regarding the distribution of the stress in the resonatorelement 10, Sb is rapidly reduced compared with Sa as the distance Dfrom the intersection 53 becomes longer. Further, in FIG. 3B, Sb isreduced compared with Sa in the entire range of D=d1, D=d2, and D=d3.That is, the distribution of the stress generated in the resonation area11 c of the crystal resonator 100 b which satisfies the relationshipexpressed by L1=W2 becomes smaller than the distribution of the stressgenerated in the resonation area 11 c of the crystal resonator 100 awhich satisfies the relationship expressed by L1=W1.

As described above, the stress distribution in the resonator element 10changes in accordance with the distance L1 between the first bondingcenter 41 b and the second bonding center 42 b, and in a case where thedistance L1 is short the stress applied into the resonation area 11 ccan be reduced compared with a case where the distance L1 is long.

However, in some cases, the stress applied into the resonation area 11 ccannot be reduced only by defining the length of the distance L1. Thereason for this is that the distance L2 between the resonation areacenter 11 d and the intersection 53 can be flexibly set as long as theexcitation electrode 13 a does not directly come in contact with thefirst bonding member 41 and the second bonding member 42, and thus theresonation area 11 c is disposed in the area in which the great stressis generated. The crystal resonator 100 b in FIG. 2A to FIG. 3B satisfythe relationship expressed by L2=d2, for example, it is possible to seta value of the distance L2 in the crystal resonator 100 b to be shorterthan the distance d2 as long as the excitation electrode 13 a does notdirectly come in contact with the first bonding member 41 and the secondbonding member 42, and in a case where the distance L2 is shorter thanthe distance d2, the distribution of the stress in the resonation area11 c becomes larger than a case of satisfying the relationship expressedby L2=d2. Note that, the same is true for a case of the crystalresonator 100 a.

From the above description, it is considered that the stressdistribution in the resonation area 11 c is not related to the absolutevalue of each of the distance L1 between the first bonding center 41 band the second bonding center 42 b and the distance L2 between theresonation area center 11 d and the intersection 53, but is related to aratio of L1 to L2.

As described above, it is considered that the crystal resonator 100including the resonator element 10 has the hysteresis in response tostress applied to the resonator element 10, and a positionalrelationship between the first bonding member 41 and the second bondingmember 42, and the resonation area 11 c is important so as to reduce thehysteresis of the crystal resonator 100. Accordingly, the inventors ofthe present application have obtained a result illustrated in FIGS. 3Aand 3B by executing an experiment based on the assumption that thehysteresis of the crystal resonator 100 is related to L1/L2 which is theratio of the distance L1 between the first bonding center 41 b and thesecond bonding center 42 b and the distance L2 between the resonationarea center 11 d and the intersection 53.

The resonator element 10 which is used in the aforementioned experimentis formed into a rectangular shape having a short side of 1.25 mm in thefirst direction 54 and a long side of 1.80 mm in the direction whichintersects with the first direction 54 as illustrated in FIG. 1A. Whenviewed from above, the excitation electrodes 12 a and 13 a are formedinto a rectangular shape and are disposed so as to substantially overlapwith each other, the short side is disposed in the direction along theshort side of the resonator element 10, and the long side is disposed inthe direction along the long side of the resonator element 10.

The excitation electrodes 12 a and 13 a are formed into a rectangularhaving a short side of 0.90 mm and a long side of 1.08 mm.

The center of the resonator element 10 and the center of the respectiveexcitation electrodes 12 a and 13 a substantially overlap the firstvirtual line 51. The resonation area 11 c substantially overlaps thecenter of the each of the excitation electrodes 12 a and 13 a whenviewed from above, and thus the resonation area 11 c is disposedsubstantially in the same position as that of the excitation electrodes12 a and 13 a with the same scale.

The first bonding center 41 b and the second bonding center 42 b arearranged in the direction along the first side 11 e and the distancebetween the first bonding center 41 b and the first side 11 e and thedistance between the second bonding center 42 b and the first side 11 eare 0.175 mm when viewed from above.

In addition, the resonator element 10, the excitation electrodes 12 aand 13 a, and the resonation area 11 c are disposed to be substantiallyline symmetry with respect to the second virtual line 52 when viewedfrom above, and the distance between the resonation area center 11 d andthe intersection 53 is 0.825 mm. In addition, in the experiment of theembodiment, the upper surface 41 a of the first bonding member 41 andthe upper surface 42 a of the second bonding member 42 are respectivelya circle having a diameter of 0.35 mm centering the first bonding center41 b and a circle having a diameter of 0.35 mm centering the secondbonding center 42 b. In addition, in the experiment, the value of L1/L2is changed by setting the distance L2 between the resonation area center11 d and the intersection 53 to be substantially constant and changingthe distance L1 between the first bonding center 41 b and the secondbonding center 42 b.

FIG. 4 is a diagram illustrating a relationship between L1/L2 and thehysteresis of the crystal resonator 100. Here, as described later, thehysteresis is the maximum value of the absolute value of the differencebetween the resonance frequency when the temperature is decreased andthe resonance frequency when the temperature is increased in eachtemperature, which is acquired by measuring the resonance frequency ofthe crystal resonator 100 in each temperature when the temperature isdecreased and the resonance frequency of the crystal resonator 100 ineach temperature when the temperature is increased.

In addition, in FIG. 4, the hysteresis of the crystal resonator 100 ismeasured and acquired in the following manner. In the experiment, thehysteresises of the crystal resonator 100 having five types of ratios ofL1/L2 which are 0.36, 0.50, 0.70, 0.80, and 0.90 are measured andacquired. In the experiment, the hysteresis of the crystal resonator 100is measured and acquired through the following methods.

First, the ambient temperature of the crystal resonator 100 is increasedfrom room temperature (+25° C.) up to +85° C. Then, the resonancefrequency of the crystal resonator 100 is measured at a 5° C. oftemperature interval when the temperature is decreased by decreasing theambient temperature of the crystal resonator 100 from +85° C. up to −40°C. Next, by heating the crystal resonator 100 such that the ambienttemperature is increased from −40° C. up to +85° C., when thetemperature is increased, the resonance frequency of the crystalresonator 100 is measured at a temperature at which the resonancefrequency is measured when the temperature is decreased. Then, afrequency difference, which is the difference between the resonancefrequency when the temperature is decreased and the resonance frequencywhen the temperature is increased, is acquired with respect to theresonance frequencies of the crystal resonator 100 which are measuredwhen the temperature is decreased and increased under the sametemperature condition. Subsequently, the frequency difference obtainedunder the respective temperature conditions is normalized by a norminalfrequency (the resonance frequency at room temperature (+25° C.)) of thecrystal resonator 100, and then the normalized frequencies under therespective temperature conditions are acquired. Lastly, a value of whichthe absolute value becomes the maximum is acquired among the normalizedfrequencies under the respective temperature conditions, and theacquired value is extracted as the hysteresis of the crystal resonator100. The hysteresises of the crystal resonator 100 in each of ratios ofL1/L2 is calculated by performing the above measurement on the crystalresonator 100 having the five types of ratios of L1/L2 which are used inthe experiment.

From FIG. 4, it is found that when L1/L2 which is the ratio of thedistance L1 between the first bonding center 41 b and the second bondingcenter 42 b, and the distance L2 between the resonation area center 11 dand the intersection 53 is 0.97, the hysteresis of the crystal resonator100 is 0.07 ppm. In addition, from FIG. 4, it is found that when a valuesmaller than 0.36 is input to the ratio of L1/L2, the hysteresis of thecrystal resonator 100 becomes further smaller. Accordingly, in a rangeof 0<L1/L2≦0.97, the hysteresis of the crystal resonator 100 is 0.07 ppmor less. In addition, when L1/L2=0.85 is satisfied, the hysteresis ofthe crystal resonator 100 becomes 0.05 ppm. Accordingly, in a range of0<L1/L2≦0.85, the hysteresis of the crystal resonator 100 is 0.05 ppm orless.

In a case where the crystal resonator 100 or an oscillator which usesthe crystal resonator 100 is used for a product such as an electronicapparatus as a reference frequency source, the absolute value of thehysteresis of the crystal resonator 100 is required to be small so asnot to reduce performance of the electronic apparatus. Particularly, ina case where the crystal resonator 100 or the oscillator which uses thecrystal resonator 100 is used for, for example, a reference frequencysource of a femtocell base station of a mobile phone and the like, thevariation in the frequency-temperature characteristics of the crystalresonator 100 or the oscillator which uses the crystal resonator 100 isrequired to be 0.25 ppm or less, and in order to satisfy this value, thehysteresis is required to be 0.1 ppm or less. Accordingly, thehysteresis of the oscillator which uses the crystal resonator 100 andthe crystal resonator 100 is preferably 0.07 ppm or less.

In addition, in a case where the crystal resonator 100 or the oscillatorwhich uses the crystal resonator 100 is used for the electronicapparatus requiring higher frequency accuracy, for example, a devicewhich is synchronized with a GPS signal, a macrocell base station of amobile phone, a base station device for optical network (a basic system)and the like, the hysteresis of the crystal resonator 100 or theoscillator which uses the crystal resonator 100 is preferably 0.05 ppmor less.

As described above, according to the crystal resonator 100 in theembodiment, it is possible to obtain the following effects. In thecrystal resonator 100, for example, even in a case where the stress isgenerated due to a difference between the elongation amount or theshrinkage amount of the resonator element 10 and the elongation amountor the shrinkage amount of the bottom plate 21 in accordance with thechange of the ambient temperature of the crystal resonator 100, L1/L2satisfies a relationship expressed by 0<L1/L2≦0.97, and thus it ispossible to reduce the stress so as not to be transferred to theresonation area 11 c of the resonator element 10. As a result, it ispossible to reduce the variation in characteristics of the crystalresonator 100, for example, the value of hysteresis.

In addition, in the crystal resonator 100, for example, even in a casewhere the stress is generated due to a difference between the elongationamount or the shrinkage amount of the resonator element 10 and theelongation amount or the shrinkage amount of the bottom plate 21 inaccordance with the change of the ambient temperature of the crystalresonator 100, L1/L2 satisfies a relationship expressed by 0<L1/L2≦0.85and thus it is possible to further reduce the stress so as not to betransferred to the resonation area 11 c of the resonator element 10. Asa result, it is possible to further reduce the variation incharacteristics of the crystal resonator 100, for example, the value ofhysteresis compared with the case where L1/L2 satisfies the relationshipexpressed by 0<L1/L2≦0.97.

Meanwhile, in the experiment, the diameter of each of the upper surface41 a of the first bonding member 41 and the upper surface 42 a of thesecond bonding member 42 is 0.35 mm, and thus as a lower limit of thedistance L1 is preferably greater than 0.35 mm which is in a range thatthe first bonding member 41 and the second bonding member 42 are notelectrically connected to each other. That is, it is preferable thatL1/L2 satisfies a relationship expressed by 0.425<L1/L2≦0.97.

Further, in a case where the first bonding member 41 and the secondbonding member 42 are formed of an electroconductive adhesive, thediameter of each of the upper surface 41 a of the first bonding member41 and the upper surface 42 a of the second bonding member 42 can be0.15 mm or smaller, and thus as a lower limit of the distance L1 ispreferably greater than 0.15 mm which is in a range that the firstbonding member 41 and the second bonding member 42 are not electricallyconnected to each other. That is, it is preferable that L1/L2 satisfiesa relationship expressed by 0.185<L1/L2≦0.97.

In addition, the measurement of the resonance frequency when the ambienttemperature of the crystal resonator 100 is decreased is performed firstin the experiment; however, the order of measurement is not limited, forexample, the measurement of the resonance frequency when the ambienttemperature of the crystal resonator 100 is increased may be performedfirst. In addition, the measurement may be not necessarily performed atthe 5° C. of temperature interval as long as the hysteresis can becalculated, for example, the temperature interval may be in a range of0.5° C. to 10° C. Further, the room temperature is set to be +25° C. inthe experiment; however, room temperature may be, for example, in arange of 0° C. to +40° C.

In addition, in the embodiment, the crystal substrate 11 is used as theresonator element 10; however, the resonator element 10 may be formed ofanother piezoelectric single crystal such as lithium niobate and lithiumtantalite. In a case where the resonator element 10 is formed of apiezoelectric single crystal other than the crystal, the orientation ofcrystal (a cut angle) or the like is selected so as to obtain the samecharacteristics as in the case of being formed of the crystal. Anelastic surface wave element and a MEMS resonator element other than thepiezoelectric resonator element can be used for the resonator element10. In addition, the resonator element 10 may be formed of apiezoelectric material of piezoelectric ceramics such as lead zirconatetitanate, or a silicon substrate other than the piezoelectric singlecrystal. Further, the shape of the resonator element 10 is notparticularly limited, for example, it may be a bipod tuning fork, anH-type tuning fork, a tripod tuning fork, a comb type, an orthogonaltype, a prismatic type or the like. As means for resonating theresonator element 10, a substance obtained by a piezoelectric effect oran electrostatic drive by coulomb force may be used. In addition, theresonator element 10 may be an element for detecting the physicalquantity, for example, an element for an inertial sensor (anacceleration sensor, a gyro sensor, and the like), and a force sensor (atilt sensor and the like).

In addition, the shapes and the sizes of the resonator element 10, andthe excitation electrodes 12 a and 13 a may be variously modifiedwithout being limited to the shapes of the sizes which are used in theexperiment. Further, the shapes and the sizes of the upper surface 41 aof the first bonding member 41 and the upper surface 42 a of the secondbonding member 42 may be variously modified without being limited to theshapes and the sizes which are used in the experiment.

In addition, the first bonding member 41 and the second bonding member42 use the conductive member in the embodiment; however, at least one ofthe first bonding member 41 and the second bonding member 42 may be anon-conductive member, for example, a resin or glass which does notcontain a conductive member. In a case where the first bonding member 41and the second bonding member 42 are non-conductive members, forexample, the resonator element 10 is mechanically supported by thebottom plate 21 via the first bonding member 41 and the second bondingmember 42, and the excitation electrode 12 a and the internal connectionterminal 24 a, and the excitation electrode 13 a and the internalconnection terminal 24 b can be electrically connected to each other viathe conductive member such as a bonding wire. In addition, even in acase where one of the first bonding member 41 and the second bondingmember 42 is a conductive member and the other one is a non-conductivemember, it is possible to perform the mechanical and electricalconnection on the bonding member side of the non-conductive member inthe same way as above and to perform the mechanical and electricalconnection on the bonding member side of the conductive member in thesame way as in the first embodiment.

As described above, even when the non-conductive member is used as atleast one of the first bonding member 41 and the second bonding member42, it is possible to obtain some effects of the first embodiment. Thatis, even when the non-conductive member is used as at least one of thefirst bonding member 41 and the second bonding member 42, the resonatorelement 10 is mechanically connected to the bottom plate 21 via thefirst bonding member 41 and the second bonding member 42. Accordingly,when the resonation area 11 c, the first bonding member 41, and thesecond bonding member 42 satisfy the relationship expressed by0<L1/L2≦0.97, it is possible to reduce the stress, which is generateddue to the difference between the elongation amount or the shrinkageamount of the resonator element 10 and the elongation amount or theshrinkage amount of the bottom plate 21, so as not to be transferred tothe resonation area 11 c of the resonator element 10 in accordance withthe change of the ambient temperature of the crystal resonator 100. As aresult, it is possible to reduce the variation in characteristics of thecrystal resonator 100, for example, the value of the hysteresis.

Further, in the present embodiment, the crystal resonator 100 includingthe resonator element 10 is exemplified as an example of the resonationdevice; however, it is possible to employ various types of theresonation devices. The resonation device may be a sensor such as aninertial sensor (an acceleration sensor, a gyro sensor, and the like)and a force sensor (a tilt sensor and the like), which includes anelement for detecting the physical quantity, a detection circuit fordetecting a signal from the element, or an oscillation circuit foroscillating the element. The aforementioned oscillation circuit anddetection circuit may be disposed, for example, on the inner space 26side of the bottom plate 21, or may be disposed on the side, on whichthe plurality of external connection terminals 25 are formed, of thebottom plate 21. In addition, The aforementioned oscillation circuit anddetection circuit are disposed on the side separated from the resonationdevice, and thus may be electrically connected to the resonator element10 via the plurality of external connection terminals 25 of theresonation device.

Second Embodiment

As an example of the resonation device according to the secondembodiment, a crystal resonator 200 will be described. Note that, thesame constituent element as in the crystal resonator 100 in the firstembodiment is given the same reference numerals, repeated descriptionwill be omitted, and the description will focus on the differences fromthe crystal resonator 100 in the first embodiment.

FIGS. 5A and 5B are schematic configuration diagrams of the crystalresonator 200 as the resonation device according to the secondembodiment, and FIG. 5A is a plan view and FIG. 5B is a sectional viewtaken along line B-B of FIG. 5A.

Resonator Element

As illustrated in FIGS. 5A and 5B, unlike the first embodiment, aresonator element 110 of the crystal resonator 200 includes a hollow 111f, which is on a lower surface 111 b side of a crystal substrate 111being formed, between the first virtual line 51 which connects the firstbonding center 41 b and the second bonding center 42 b and an excitationelectrode 113 a on the lower surface 111 b when viewed from above. Inaddition, the hollow 111 f extends to the second bonding center 42 bfrom the first bonding center 41 b in the direction along the firstdirection 54.

In the hollow 111 f, a distance in a direction which intersects with anupper surface 111 a and the lower surface 111 b of the crystal substrate111, that is, a thickness T1 of the hollow 111 f is smaller than athickness T2 of the crystal substrate 111 in which the hollow 111 f isnot formed. In addition, the hollow 111 f is formed in the insidefurther than an end portion of the crystal substrate 111 in the firstdirection 54 when viewed from above.

In the crystal resonator 200 in the embodiment, the stress which isgenerated due to the difference between the elongation amount or theshrinkage amount of the resonator element 110 and the elongation amountor the shrinkage amount of the bottom plate 21 in accordance with thechange of the ambient temperature of the crystal resonator 200 istransferred to a resonation area 111 c of the resonator element 110,that is, the stress is transferred to the resonation area 111 c which isan area which overlaps excitation electrodes 112 a and 113 a in thecrystal substrate 111 of FIG. 5A, and a hatched area in the crystalsubstrate 111 of FIG. 5B via an area in the hollow 111 f. The thicknessT1 of the hollow 111 f on the crystal substrate 111 is smaller than thethickness T2 of the crystal substrate 111. In a case where the stress istransferred to the area in the thickness T2 via the area in thethickness T1, the stress is absorbed into the area in the thickness T1which is largely distorted compared with the area in the thickness T2,and thus the stress transferred to the area in the thickness T2 isreduced. Accordingly, the stress which is generated due to thedifference between the elongation amount or the shrinkage amount theresonator element 110 and the elongation amount or the shrinkage amountof the bottom plate 21 as the substrate in accordance with the change ofthe ambient temperature of the crystal resonator 200 is less likely tobe transferred to the resonation area 111 c by distorting the hollow 111f.

As described above, according to the crystal resonator 200 in theembodiment, in a case where the resonation area 111 c, the first bondingmember 41, and the second bonding member 42 satisfy a relationshipexpressed by 0<L1/L2≦0.97, in addition to the effect resulting from thecrystal resonator 100 in the first embodiment, the following effects canbe obtained. In the crystal resonator 200 of the embodiment, comparedwith the first embodiment, the stress which is generated due to thedifference between the elongation amount or the shrinkage amount theresonator element 110 and the elongation amount or the shrinkage amountof the bottom plate 21 in accordance with the change of the ambienttemperature, and is transferred to the resonation area 11 c is furtherreduced. Accordingly, it is possible to further reduce the variation incharacteristics of the crystal resonator 200, for example, the value ofhysteresis compared with the first embodiment.

Meanwhile, the hollow 111 f may be formed in any position other than theposition defined in the embodiment. For example, when viewed from above,the hollow 111 f may be separately formed in two or more portions whichare between the first bonding center 41 b and the excitation electrodes112 a and 113 a, and between the second bonding center 42 b and theexcitation electrodes 112 a and 113 a. Further, two or more hollows 111f may be formed between the first virtual line 51 and the excitationelectrodes 112 a and 113 a in the direction which intersects with thefirst direction 54.

Third Embodiment

As an example of a resonation device according to the third embodiment,a crystal resonator 300 will be described. Note that, the sameconstituent element as in the crystal resonator 100 in the firstembodiment is given the same reference numerals, repeated descriptionwill be omitted, and the description will focus on the differences fromthe crystal resonator 100 in the first embodiment.

FIGS. 6A and 6B are schematic configuration diagrams of a crystalresonator 300 as the resonation device according to the thirdembodiment, and FIG. 6A is a plan view and FIG. 6B is a sectional viewtaken along line C-C of FIG. 6A.

Resonator Element

As illustrated in FIGS. 6A and 6B, unlike the first embodiment, aresonator element 210 of the crystal resonator 300 includes a hole 211g, which penetrates from the upper surface 211 a to the lower surface211 b on the crystal substrate 211, between the first virtual line 51which connects the first bonding center 41 b and the second bondingcenter 42 b and excitation electrodes 212 a and 213 a, when viewed fromabove. In addition, the hole 211 g extends to the second bonding center42 b from the first bonding center 41 b in the direction along the firstdirection 54.

In the crystal resonator 300 of the present embodiment, the stress whichis generated due to the difference between the elongation amount or theshrinkage amount of the resonator element 210 and the elongation amountor the shrinkage amount of the bottom plate 21 in accordance with thechange of the ambient temperature is transferred to a resonation area211 c of the resonator element 210, that is, the stress is transferredto the resonation area 211 c which is an area which overlaps excitationelectrodes 212 a and 213 a in the crystal substrate 211 of FIG. 6A, anda hatched area in the crystal substrate 211 of FIG. 6B via both an areawhich is not adjacent to the hole 211 g and an area which is adjacent tothe hole 211 g of the crystal substrate 211. The area adjacent to thehole 211 g of the crystal substrate 211 is more easily distorted thanthe area which is not adjacent to the hole 211 g. As a result, thestress which is generated due to the difference between the elongationamount or the shrinkage amount of the resonator element 210 and theelongation amount or the shrinkage amount of the bottom plate 21 inaccordance with the change of the ambient temperature of the crystalresonator 300 is less likely to be transferred to the resonation area211 c by distorting the area adjacent to the hole 211 g.

As described above, according to the crystal resonator 300 in theembodiment, in a case where the resonation area 211 c, the first bondingmember 41, and the second bonding member 42 satisfy a relationshipexpressed by 0<L1/L2≦0.97, in addition to the effect resulting from thecrystal resonator 100 in the first embodiment, the following effects canbe obtained. In the crystal resonator 300 of the embodiment, comparedwith the first embodiment, the stress which is generated due to thedifference between the elongation amount or the shrinkage amount theresonator element 210 and the elongation amount or the shrinkage amountof the bottom plate 21 in accordance with the change of the ambienttemperature of the crystal resonator 300, and is transferred to theresonation area 211 c is further reduced. Accordingly, compared with thefirst embodiment, it is possible to further reduce the variation incharacteristics of the crystal resonator 300, for example, the value ofhysteresis compared with the first embodiment.

Meanwhile, the hole 211 g may be formed in any position other than theposition defined in the embodiment. For example, when viewed from above,the hole 211 g may be separately formed in two or more portions whichare between the first bonding center 41 b and the excitation electrodes212 a and 213 a, and between the second bonding center 42 b and theexcitation electrodes 212 a and 213 a. Further, two or more holes 211 gmay be formed between the first virtual line 51 and the excitationelectrodes 212 a and 213 a in the direction which intersects with thefirst direction 54.

Fourth Embodiment

As an example of the resonation device according to the fourthembodiment, a crystal resonator 400 will be described. Note that, thesame constituent element as in the crystal resonator 100 in the firstembodiment is given the same reference numerals, repeated descriptionwill be omitted, and the description will focus on the differences fromthe crystal resonator 100 in the first embodiment.

FIGS. 7A and 7C are schematic configuration diagrams of the crystalresonator 400 as a resonation device according to the fourth embodiment,and FIG. 7A is a plan view, FIG. 7B is a sectional view taken along lineD-D of FIG. 7A, and FIG. 7C is a sectional view of a part of anexcitation electrode portion of FIG. 7B.

Resonator Element

The resonator element 310 of the crystal resonator 400 in the embodimenthas a so-called mesa structure in which a first area 311 h having afirst thickness T3 and a second area 311 k having a thickness T4 whichis smaller than the thickness T3 are included within a distance in adirection which intersects with an upper surface and a lower surface ofa crystal substrate 311, that is, the thickness of a crystal substrate311. The crystal substrate 311 has a shape in which the first area 311 his surrounded by the second area 311 k when viewed from above.

As illustrated in FIG. 7A, excitation electrodes 312 a and 313 a areformed into a rectangular shape when viewed from above, and are disposedso as to substantially overlap with each other. That is, when viewedfrom above, the center of the excitation electrode 312 a and the centerof the excitation electrode 313 a are disposed so as to substantiallyoverlap with each other. In addition, the crystal substrate 311 includesa resonation area 311 c which is interposed between the excitationelectrodes 312 a and 313 a, that is, an area which overlaps theexcitation electrodes 312 a and 313 a in the crystal substrate 311 ofFIG. 7A, and a hatched area in the crystal substrate 311 of FIG. 7B.Further, the excitation electrodes 312 a and 313 a are disposed so as tooverlap the first area 311 h in the first direction 54, and are disposedso as to overlap the first area 311 h and the second area 311 k in thedirection which intersects with the first direction 54 when viewed fromabove.

The resonation area 311 c includes the resonation area center 311 d.Since the excitation electrodes 312 a and 313 a are disposed asdescribed above, the resonation area 311 c is formed into a rectangularshape when viewed from above, and the resonation area center 311 d andthe center of each of excitation electrodes 312 a and 313 asubstantially overlap with each other.

The resonation area center 311 d and the center of the first area 311 hare disposed so as to substantially overlap with each other when viewedfrom above. In addition, in the embodiment, the first area 311 hoverlaps a large part of the resonation area 311 c. The large part ofthe resonation area 311 c is preferably equal to or greater than 80%,for example. Meanwhile, the center of each of the excitation electrodes312 a and 313 a, the resonation area center 311 d, and the center of thefirst area 311 h are respectively the centroid (the center of a drawing)of a shape when the excitation electrodes 312 a and 313 a are viewedfrom above, the centroid (the center of a drawing) of a shape when theresonation area 311 c is viewed from above, and the centroid (the centerof a drawing) of a shape when the first area 311 h is viewed from above.

In addition, as illustrated in FIGS. 7B and 7C, the excitation electrode312 a is disposed so as to cover the upper surface of the first area 311h, a side surface 311 m which connects the upper surface of the firstarea 311 h and the upper surface of the second area 311 k, and the uppersurface of the second area 311 k in the direction which intersects withthe first direction 54. The excitation electrode 313 a is disposed so asto cover the lower surface of the first area 311 h, a side surface 311 nwhich connects the lower surface of the first area 311 h and the lowersurface of the second area 311 k, and the lower surface of the secondarea 311 k in the direction which intersects with the first direction54.

In the crystal resonator 400 in the embodiment, when viewed from above,the resonation area center 311 d overlaps the first area 311 h having afirst thickness T3 and the first bonding center 41 b and the secondbonding center 42 b overlap the second area 311 k having the thicknessT4 which is smaller than the thickness T3. That is, the resonatorelement 310 is supported by the bottom plate 21 via the first bondingmember 41 and the second bonding member 42 in the second area 311 khaving the thickness T4 which is smaller than the thickness T3 of thefirst area 311 h in which a large amount of resonation energy isconcentrated while the resonator element 310 resonates. For this reason,the stress, which is generated due to the difference between theelongation amount or the shrinkage amount the resonator element 310, andthe elongation amount or the shrinkage amount of the bottom plate 21 asthe substrate in accordance with the change of the ambient temperatureof crystal resonator 400 is transferred to the resonation area 311 c viathe second area 311 k. In a case where the stress is transferred to thearea in the thickness T3 via the area in the thickness T4, the stress isabsorbed into the area in the thickness T4 which is largely distortedcompared with the area in the thickness T3, and thus the stresstransferred to the area in the thickness T3 is reduced. Accordingly, thestress, which is generated due to the difference between the elongationamount or the shrinkage amount of the resonator element 310, and theelongation amount or the shrinkage amount of the bottom plate 21 inaccordance with the change of the ambient temperature of crystalresonator 400 is less likely to be transferred to the resonation area311 c by distorting the second area 311 k of the resonator element 310.

As described above, according to the crystal resonator 400 in theembodiment, in a case where the resonation area 311 c, the first bondingmember 41, and the second bonding member 42 satisfy a relationshipexpressed by 0<L1/L2≦0.97, in addition the effect resulting from thecrystal resonator 100 in the first embodiment, the following effects canbe obtained. In the crystal resonator 400 of the embodiment, comparedwith the first embodiment, the stress which is generated due to thedifference between the elongation amount or the shrinkage amount theresonator element 310 and the elongation amount or the shrinkage amountof the bottom plate 21 in accordance with the change of the ambienttemperature of the crystal resonator 400, and is transferred to theresonation area 311 c is further reduced. Accordingly, compared with thefirst embodiment, it is possible to further reduce the variation incharacteristics of the crystal resonator 400, for example, the value ofhysteresis.

Meanwhile, the resonator element 310 in the embodiment is disposed insuch a manner that when viewed from above, the center of each of theexcitation electrodes 312 a and 313 a, the resonation area center 311 d,and the center of the first area 311 h substantially overlap with eachother; however, it is not limited thereto as long as the excitationelectrodes 312 a and 313 a are disposed such that the resonation areacenter 311 d and the first area 311 h overlap with each other whenviewed from above. In addition, the excitation electrodes 312 a and 313a may be disposed such that when viewed from above, one excitationelectrode is disposed in the inner side of the other excitationelectrode, or both excitation electrodes 312 a and 313 a may be disposedso as to overlap only the first area 311 h.

Modification Example of Resonator Element

In the resonation device of the embodiment, the resonator element is notnecessarily to be a shape of the resonator element 310 as illustrated inFIGS. 7A to 7C. Modification Example of the resonator element will bedescribed with reference to FIGS. 8A to 8E. Note that, the sameconstituent element as that of the resonator element 10 in the firstembodiment or the resonator element 310 in the fourth embodiment isgiven the same reference numerals, repeated description will be omitted,and the description will focus on the differences from the resonatorelement 10 the first embodiment or the resonator element 310 in thefourth embodiment.

FIGS. 8A to 8E are schematic configuration diagrams illustratingModification Example of the resonator element according to theembodiment, FIG. 8A is a plan view of the resonator element 410 which isan example of Modification Example, FIG. 8B is a sectional view takenalong line E-E in FIG. 8A, FIG. 8C is a plan view of the resonatorelement 510 which is another example of Modification Example, FIG. 8D isa sectional view taken along line F-F in FIG. 8C, and FIG. 8E is apartially enlarged sectional view of an excitation electrode portion inFIG. 8D. Note that, in the following description, an upper side in FIGS.8B and 8D is referred to as “up” and a lower side is referred to as“down”. In addition, a surface on the upper side of each member in FIGS.8B and 8D is referred to as an upper surface, and a surface on the lowerside is referred to as a lower surface.

As illustrated in FIGS. 8A and 8B, the resonator element 410 isconfigured such that the upper surface of the first area 411 h of thecrystal substrate 411 in the thickness T3 protrudes from the uppersurface of the second area 411 k in the thickness T4, and the lowersurface of the first area 411 h and the lower surface of the second area411 k are connected to each other in a planar shape. Excitationelectrodes 412 a and 413 a are disposed so as to substantially overlapwith each other when viewed from above. In addition, the crystalsubstrate 411 includes a resonation area 411 c which is interposedbetween the excitation electrodes 412 a and 413 a, that is, an areawhich overlaps the excitation electrodes 412 a and 413 a in the crystalsubstrate 411 of FIG. 8A, and a hatched area in the crystal substrate411 of FIG. 8B. Further, the resonation area center 411 d is disposed soas to substantially overlap the center of the first area 411 h.

In addition, the excitation electrode 412 a is disposed so as to coverthe upper surface of the first area 411 h, a side surface 411 m whichconnects the upper surface of the first area 411 h and the upper surfaceof the second area 411 k, and the upper surface of the second area 411 kin the direction which intersects with the first direction 54.

As illustrated in FIGS. 8C and 8D, the resonator element 510 includes anarea in a thickness T5 in which the thickness of the first area 511 h ofthe crystal substrate 511 is greater than the thickness T4 of the secondarea 511 k, and an area in a thickness T6 which is greater than thethickness T5. In addition, the excitation electrodes 512 a and 513 a aredisposed such that the area in the thickness T6 and the area in thethickness T5 of the first area 511 h overlap the second area 511 k whenviewed from above. In addition, the crystal substrate 511 includes aresonation area 511 c which is interposed between the excitationelectrodes 512 a and 513 a, that is, an area which overlaps theexcitation electrodes 512 a and 513 a in the crystal substrate 511 ofFIG. 8C, and a hatched area in the crystal substrate 511 of FIG. 8D.Further, the resonation area center 511 d is disposed so as to overlapthe area in the thickness T6 of the first area 511 h.

In addition, as illustrated in FIGS. 8D and 8E, the excitation electrode512 a is disposed so as to cover the upper surface of the area of thefirst area 511 h in the thickness T6, a side surface 511 m whichconnects the upper surface of the area of the first area 511 h in thethickness T6 and the upper surface of the area of the first area 511 hin the thickness T5, the upper surface of the area of the first area 511h in the thickness T5, a side surface 511 n which connects the uppersurface of the area of the first area 511 h in the thickness T5 and theupper surface of the second area 511 k, and the upper surface of thesecond area 511 k in the direction which intersects with the firstdirection 54. The excitation electrode 513 a is disposed so as to coverthe lower surface of the area of the first area 511 h in the thicknessT6, a side surface 511 p which connects the lower surface of the area ofthe first area 511 h in the thickness T6 and the lower surface of thearea of the first area 511 h in the thickness T5, the lower surface ofthe area of the first area 511 h in the thickness T5, a side surface 511q which connects the lower surface of the area of the first area 511 hin the thickness T5 and the lower surface of the second area 511 k, andthe lower surface of the second area 511 k in the direction whichintersects with the first direction 54.

The crystal resonator 400 which is formed of the resonator element 410or the resonator element 510 can exhibit the same effect as the effectresulting from crystal resonator 400 which is formed of the resonatorelement 310 in the embodiment.

Meanwhile, the resonator element 410 in Modification Example asdescribed above is disposed in such a manner that when viewed fromabove, the center of each of the excitation electrodes 412 a and 413 a,the resonation area center 411 d, and the center of the first area 411 hsubstantially overlap with each other; however, it is not limitedthereto as long as the excitation electrodes 412 a and 413 a aredisposed such that the resonation area center 411 d and the first area411 h overlap with each other when viewed from above. In addition, theexcitation electrodes 412 a and 413 a may be disposed such that whenviewed from above, one excitation electrode is disposed in the innerside of the other excitation electrode, or both excitation electrodes412 a and 413 a may be disposed so as to overlap only the first area 411h.

In addition, the resonator element 510 in Modification Example asdescribed above is disposed in such a manner that when viewed fromabove, the center of each of the excitation electrodes 512 a and 513 a,the resonation area center 511 d, and the center of the first area 511 hsubstantially overlap with each other; however, it is not limitedthereto as long as the excitation electrodes 512 a and 513 a aredisposed such that the resonation area center 511 d and the area of thefirst area 511 h in the thickness T6 overlap with each other when viewedfrom above. In addition, the excitation electrodes 512 a and 513 a maybe disposed such that when viewed from above, one excitation electrodeis disposed in the inner side of the other excitation electrode, or bothexcitation electrodes 512 a and 513 a may be disposed so as to overlaponly the first area 511 h.

Fifth Embodiment

As an example of the resonation device according to the fifthembodiment, a crystal resonator 500 will be described. Note that, thesame constituent element as that of the crystal resonator 100 in thefirst embodiment is given the same reference numerals, repeateddescription will be omitted, and the description will focus on thedifferences from the crystal resonator 100 in the first embodiment.

FIGS. 9A and 9B are schematic configuration diagrams of a crystalresonator 500 as a resonation device according to the fifth embodiment,and FIG. 9A is a plan view and FIG. 9B is a sectional view taken alongline G-G of FIG. 9A.

Bonding Member

As illustrated in FIGS. 9A and 9B, unlike the crystal resonator 100 inthe first embodiment, a first bonding member 141 and a second bondingmember 142 of the crystal resonator 500 in the embodiment are formed ofa metallic bump. The connection electrode 12 c side of the first bondingmember 141, that is, an upper surface 141 a on the resonator element 10side includes a first bonding center 141 b. The connection electrode 13c side of the second bonding member 142, that is, an upper surface 142 aof the resonator element 10 side includes a second bonding center 142 b.

The metallic bump is formed by a plating method, a bonding method, orthe like. The plating method is performed by plating metal after forminga predetermined pattern such that the first bonding member 141 and thesecond bonding member 142 are formed in a predetermined position of theresonator element 10 or the package 20, and thereby the metallic bumpswhich are the first bonding member 141 and the second bonding member 142can be formed.

In addition, the bonding method is performed by connecting a metallicwire (thin wire) such as gold (Au) to a position in which each of thefirst bonding member 141 and the second bonding member 142 of theresonator element 10 or the package 20 is formed, and cutting the wireexcept for the connected part, and thereby the metallic bumps which arethe first bonding member 141 and the second bonding member 142 can beformed.

In addition, instead of the plating method and the bonding method, amethod of forming the metallic bumps which are the first bonding member141 and the second bonding member 142 by coating the position, in whichthe first bonding member 141 and the second bonding member 142 of theresonator element 10 or the package 20 are formed, with a paste(solvent) containing a metallic member by printing or dispensing, thenheating the resonator element 10 or the package 20 which is coated withthe paste so as to volatilize solvent components except for the metal,can be used.

The shape of the metallic bump is not particularly limited, for example,it may be a columnar (cylindrical) shape, a polygonal prism, a truncatedcone, and the like. In addition, the metallic wire may be formed ofmetal mainly containing silver (Ag), copper (Cu), aluminum (Al),platinum (Pt), and the like in addition to gold (Au). Further, amaterial of the metallic member may be metal mainly containing gold(Au), silver (Ag), copper (Cu), aluminum (Al), platinum (Pt), and thelike, or an alloy such as a lead-free solder or a leaded solder.

The metallic bump has less gas emission from the inside of the metallicbump due to the heat and the time elapse compared with a resin membersuch as an adhesive. For this reason, even when the crystal resonator500 is heated, and time has elapsed after manufacturing the crystalresonator 500, the gas emission from the first bonding member 141 andthe second bonding member 142 is reduced compared with a case where thefirst bonding member 141 and the second bonding member 142 are formed ofa resin member.

In addition, since the gas emitted from the first bonding member 141 andthe second bonding member 142 is emitted to the inner space 26 in anair-tight state, the emitted gas is attached to the excitationelectrodes 12 a and 13 a so as to increase a mass amount, and theemitted gas changes the excitation electrodes 12 a and 13 a, and thusthe characteristics of the resonator element 10, for example, aresonance frequency, a frequency-temperature characteristic, and anequivalent series resistance are changed in some cases.

From the above description, due to the heat and the time elapse, the gasemitted from the first bonding member 141 and the second bonding member142 of the crystal resonator 500 in the embodiment is more reduced thanthe gas emitted from the first bonding member 41 and the second bondingmember 42 of the crystal resonator 100 in the first embodiment.Accordingly, as compared with the crystal resonator 100 in the firstembodiment, it is possible to reduce the variation of thecharacteristics of the crystal resonator 500, for example, the resonancefrequency, the frequency-temperature characteristics, and the equivalentseries resistance.

As described above, according to the crystal resonator 500 in theembodiment, in a case where the resonation area 11 c, the first bondingmember 141, and the second bonding member 142 satisfy a relationshipexpressed by 0<L1/L2≦0.97, in addition the effect resulting from thecrystal resonator 100 in the first embodiment, the following effects canbe obtained. As compared with the crystal resonator 100 in the firstembodiment, it is possible to reduce the gas emitted from the firstbonding member 141 and the second bonding member 142 of the crystalresonator 500, and thus it is possible to reduce the variation of thecharacteristics of the crystal resonator 500, for example, the outputfrequency, the frequency-temperature characteristics, and the equivalentseries resistance.

Note that, the first bonding member 141 and the second bonding member142 are formed of the metallic bump in the embodiment; however, even ina case where at least one bonding member of the first bonding member 141and the second bonding member 142 may be formed of the metallic bump,and the other bonding member may be formed of a conductive ornon-conductive adhesive, and the like, it is possible to result in thesame effect as that in the embodiment from the above-describeddescription.

In addition, in a case where the first bonding member 141 and the secondbonding member 142 are formed of the metallic bump, a diameter of eachof the upper surface 141 a of the first bonding member 141 and the uppersurface 142 a of the second bonding member 142 can be set to be equal toor less than 0.05 mm, and thus it is preferable that a lower limit of L1is greater than 0.05 mm as a range in which the first bonding member 141and the second bonding member 142 are not electrically connected to eachother. in other words, it is preferable that L1/L2 satisfies arelationship expressed by 0.065<L1/L2≦0.97.

Sixth Embodiment

As an example of the resonation device according to the sixthembodiment, a crystal resonator 600 will be described. Note that, thesame constituent element as that of the crystal resonator 100 in thefirst embodiment is given the same reference numerals, repeateddescription will be omitted, and the description will focus on thedifferences from the crystal resonator 100 in the first embodiment.

FIGS. 10A and 10B are schematic configuration diagrams of the crystalresonator 600 as a resonation device according to the sixth embodiment,and FIG. 10A is a plan view and FIG. 10B is a sectional view taken alongline H-H of FIG. 10A.

As illustrated in FIGS. 10A and 10B, the crystal resonator 600 in theembodiment satisfies the relationship expressed by 0<L1/L2≦0.97 in thecrystal resonator 100 of the first embodiment, and is configured asfollows.

Here, in the crystal resonator 600, when a virtual line which passesthrough the resonation area center 11 d and is parallel to the firstdirection 54 is set to be a third virtual line 57, a distance betweenthe first bonding center 41 b and the second virtual line 52 as aperpendicular line is set to be La, a distance between the secondbonding center 42 b and the second virtual line 52 is set to be Lb, adistance between the resonation area center 11 d and an end portion 58of the resonation area 11 c, which is positioned on the first bondingmember 41 side with respect to the second virtual line 52 and intersectswith the third virtual line 57, is set to be Wa, and a distance betweenthe resonation area center 11 d and an end portion 59 of the resonationarea 11 c, which is positioned on the second bonding member 42 side withrespect to the second virtual line 52 and intersects with the thirdvirtual line 57, is set to be Wb.

Hereinafter, a relationship between La, Lb, Wa, and Wb and thehysteresis in the crystal resonator 600 will be described.

The inventors of the present application have obtained a result asindicated in FIG. 11 by executing an experiment based on the assumptionthat in addition to the configuration of the first embodiment, thehysteresis of the crystal resonator 600 is related to La/Wa which is theratio of the distance La between the first bonding center 41 b and thesecond virtual line 52 to the distance Wa between the resonation areacenter 11 d and an end portion 11 c 1 of the resonation area 11 c, orrelated to Lb/Wb which is the ratio of the distance Lb between thesecond bonding center 42 b and the second virtual line 52 to thedistance Wb between the resonation area center 11 d and an end portion11 c 2 of the resonation area 11 c.

A resonator element 610 which is used in the aforementioned experimentis basically formed into substantially the same shape as that of theresonator element 10 in first embodiment, and the excitation electrodes12 a and 13 a, and the resonation area 11 c are disposed to besubstantially line symmetry with respect to the second virtual line 52when viewed from above. Accordingly, in the experiment, it can be saidthat the relationships Wa=Wb=0.45 mm, and La=Lb are satisfied.

FIG. 11 is a diagram illustrating a relationship between Lb/Wb(Lb/Wb=La/Wa in the experiment) and a hysteresis of the crystalresonator 600. In this regards, as described above, the hysteresis isthe maximum value of the absolute value of the difference between theresonance frequency when the temperature is decreased and the resonancefrequency when the temperature is increased in each temperature, whichis acquired by measuring the resonance frequency of the crystalresonator 600 in each temperature when the temperature is decreased andthe resonance frequency of the crystal resonator 600 in each temperaturewhen the temperature is increased.

In addition, in FIG. 11, the hysteresis of the crystal resonator 600 ismeasured and acquired through the same method in the first embodiment.In the experiment, the hysteresises of the crystal resonator 600 havingfive types of ratios of Lb/Wb which are 0.40, 0.56, 0.77, 0.89, and 1.00is measured and acquired.

From FIG. 11, it is found that when Lb/Wb which is the ratio of thedistance Lb between the second bonding center 42 b and the secondvirtual line 52 to the distance Wb between the resonation area center 11d and the end portion 59 of the resonation area 11 c is 0.89, thehysteresis of the crystal resonator 600 is 0.07 ppm. In addition, fromFIG. 11, it is found that when a value smaller than 0.40 is input to theratio of Lb/Wb, the hysteresis of the crystal resonator 600 becomesfurther smaller. Accordingly, in a range of 0<Lb/Wb≦0.89, the hysteresisof the crystal resonator 600 is 0.07 ppm or less.

In addition, when Lb/Wb=0.77 is satisfied, the hysteresis of the crystalresonator 600 becomes 0.05 ppm. Accordingly, in a range of 0<Lb/Wb≦0.77,the hysteresis of the crystal resonator 600 is 0.05 ppm or less.

As described in the first embodiment, in the case where the hysteresisof the crystal resonator 600 is used for, for example, a referencefrequency source of a femtocell base station device of a mobile phoneand the like, the hysteresis is preferably 0.07 ppm or less, and in acase where the hysteresis of the crystal resonator 600 is used for, forexample, a device which is synchronized with a GPS signal and amacrocell base station device of a mobile phone which require the highfrequency accuracy, the hysteresis is preferably 0.05 ppm or less.

As described above, according to the crystal resonator 600 in theembodiment, it is possible to obtain the following effects in additionto the effect resulting from the crystal resonator 100 in the firstembodiment. In the crystal resonator 600, for example, even in a casewhere the stress is generated due to a difference between the elongationamount or the shrinkage amount of the resonator element 610 and theelongation amount or the shrinkage amount of the bottom plate 21 inaccordance with the change of the ambient temperature of the crystalresonator 600, Lb/Wb satisfies a relationship expressed by 0<Lb/Wb≦0.89,and thus it is possible to reduce the stress so as not to be transferredto the resonation area 11 c of the resonator element 610. As a result,it is possible to reduce the variation in characteristics of the crystalresonator 600, for example, the value of hysteresis.

In addition, in the crystal resonator 600, for example, even in a casewhere the stress is generated due to a difference between the elongationamount or the shrinkage amount of the resonator element 610 and theelongation amount or the shrinkage amount of the bottom plate 21 inaccordance with the change of the ambient temperature of the crystalresonator 600, Lb/Wb satisfies a relationship expressed by 0<Lb/Wb≦0.77and thus it is possible to further reduce the stress so as not to betransferred to the resonation area 11 c of the resonator element 610. Asa result, it is possible to reduce the variation in characteristics ofthe crystal resonator 600, for example, the value of hysteresis by 28%or more than the case where Lb/Wb satisfies a relationship expressed by0<Lb/Wb≦0.89.

Meanwhile, the experiment regarding Lb/Wb is performed when La=Lb andWa=Wb are satisfied; however, La=Lb and Wa=Wb may not be necessarilysatisfied. In this case, the experiment regarding Lb/Wb may be performedas long as the relationship expressed by 0<La/Wa≦0.89 or 0<La/Wa≦0.77 issatisfied in a case of La/Wb>Lb/Wb, and the relationship expressed by0<Lb/Wb≦0.89 or 0<Lb/Wb≦0.77 is satisfied in a case of La/Wa≦Lb/Wb. Thereason for this is that the larger one of La/Wa and Lb/Wb easilytransfers the stress with respect to the resonation area 11 c, that is,the larger one of La/Wa and Lb/Wb easily transfers the stress to thewider range of the resonation area 11 c.

In addition, as in the first embodiment, even when the non-conductivemember is used as at least one of the first bonding member 41 and thesecond bonding member 42, it is possible to obtain some effects of thefirst embodiment. That is, even when the non-conductive member is usedas at least one of the first bonding member 41 and the second bondingmember 42, the resonator element 610 is mechanically connected to thebottom plate 21 via the first bonding member 41 and the second bondingmember 42. Accordingly, when the first bonding member 41 and the secondbonding member 42 satisfy the relationships expressed by 0<La/Wa≦0.89and 0<Lb/Wb≦0.89 in cases of La/Wa>Lb/Wb and La/Wa<Lb/Wb, it is possibleto reduce the stress, which is generated due to the difference betweenthe elongation amount or the shrinkage amount of the resonator element610 and the elongation amount or the shrinkage amount of the bottomplate 21, so as not to be transferred to the resonation area 11 c of theresonator element 610 in accordance with the change of the ambienttemperature of the crystal resonator 600. As a result, it is possible toreduce the variation in characteristics of the crystal resonator 600,for example, the value of the hysteresis.

Meanwhile, in the embodiment, a configuration such that when therelationship expressed by 0<L1/L2≦0.97 is satisfied in the crystalresonator 100 of the first embodiment, relationships expressed by0<La/Wa≦0.89 and 0<Lb/Wb≦0.89 are satisfied in cases of La/Wa>Lb/Wb andLa/Wa<Lb/Wb is described; however, it is possible to obtain the sameeffect even with a configuration such that only the relationshipsexpressed by 0<La/Wa≦0.89 and 0<Lb/Wb≦0.89 are satisfied in the cases ofLa/Wa>Lb/Wb and La/Wa<Lb/Wb is described.

Note that, the invention is not limited to the above-describedembodiments, but can be performed by changing or modifying theabove-described embodiments in various ways, or combining two or more ofembodiments among the above-described embodiments.

Seventh Embodiment

Next, an oscillator of the seventh embodiment which includes any one ofthe crystal resonators 100, 200, 300, 400, 500, and 600 in the firstembodiment to the sixth embodiment will be described with reference toFIGS. 12A and 12B. In addition, an example of using the crystalresonator 100 of the first embodiment as the resonation device isdescribed in the present embodiment.

FIGS. 12A and 12B are schematic configuration diagrams of an oscillator1000 as one example of the oscillator which includes the crystalresonator 100 according to the embodiment of the invention, and FIG. 12Ais a plan view and FIG. 12B is a sectional view taken along line J-J ofFIG. 12A. Note that, for the sake of convenience of description, a lid1020 is not shown in FIG. 12A. In addition, in the followingdescription, an upper side in FIG. 12B is referred to as “up” and alower side is referred to as “down”, and a surface on the upper side ofeach member in FIG. 12B is referred to as an upper surface, and asurface on the lower side is referred to as a lower surface.

As illustrated in FIGS. 12A and 12B, the oscillator 1000 is formed ofthe crystal resonator 100, a container 1010, the lid 1020, anoscillation circuit 1030, a bonding wire 1040, and the like.

The container 1010 includes an inner space 1018 of which the centerportion is depressed, and is provided with a seal ring 1012 which isformed into a frame shape along the upper surface of the container 1010,a plurality of internal connection terminals 1014 on a surface on theinner space 1018 side, and a plurality of external connection terminals1016 on the lower surface. The internal connection terminal 1014 and theexternal connection terminal 1016 are electrically connected to eachother via an internal wire (not shown).

The crystal resonator 100 is mounted on the inner space 1018 side of thecontainer 1010, and is electrically connected to the internal connectionterminal 1014 via the internal wire (not shown).

The oscillation circuit 1030 is a circuit for oscillating the crystalresonator 100, includes a plurality of pads 1032 on the upper surfacethereof, and is on the upper surface (one surface) of the crystalresonator 100 via a bonding member (not shown), for example, an adhesiveand a solder.

The bonding wire 1040 is a metallic wire (thin wire) such as gold (Au),and is electrically connected to the pad 1032 and the internalconnection terminal 1014.

The lid 1020 is formed into a flat plate-like shape which covers anopening of the container 1010, and is bonded to the seal ring 1012 suchthat the inner space 1018 of the container 1010 is in an air-tightstate.

A voltage for causing at least one terminal in the plurality of externalconnection terminals 1016 to operate the oscillation circuit 1030 isapplied to the above-described oscillator 1000, an oscillating signalwhich is output from the oscillation circuit 1030 is output from the atleast one terminal in the plurality of external connection terminals1016, that is, the other terminal of the external connection terminals1016.

As described above, when the oscillator 1000 as an example of theoscillator is provided with the crystal resonator 100 according to theembodiment of the invention, a stable frequency signal is output fromthe crystal resonator 100 as a reference frequency source of theoscillator, and thus it is possible to improve reliability of theoperation of the oscillator 1000.

Eighth Embodiment

Next, an electronic apparatus of the eighth embodiment which includesany one of the crystal resonators 100, 200, 300, 400, 500, and 600 inthe first embodiment to the sixth embodiment will be described withreference to FIG. 13 to FIG. 15. In addition, in the description of theembodiment, an example is described with reference the crystal resonator100 in the first embodiment as the resonation device.

FIG. 13 is a perspective view illustrating a configuration of amobile-type (or a Note book-type) personal computer 1100 as an exampleof an electronic apparatus which includes the crystal resonator 100 inthe first embodiment. As illustrated in FIG. 13, the personal computer1100 is formed of a main body portion 1104 which includes a key board1102, and a display unit 1108 which includes a display 1106, and thedisplay unit 1108 is rotatably supported with respect to main bodyportion 1104 via a hinge structure. The crystal resonator 100 is builtin such a personal computer 1100.

As described above, when the mobile-type (or the note book-type)personal computer 1100 as an example of the electronic apparatus isprovided with the crystal resonator 100 according to the embodiment ofthe invention, for example, as a clock source, a stable frequency signalis output from the crystal resonator 100 as a clock source which issupplied to the mobile-type personal computer 1100, and thus it ispossible to improve reliability of the operation of the mobile-typepersonal computer 1100.

FIG. 14 is a perspective view schematically illustrating a configurationof a mobile phone 1200 (including PHS) as an example of the electronicapparatus which includes the crystal resonator 100 of the firstembodiment. As illustrated in FIG. 14, the mobile phone 1200 is providedwith a plurality of operation buttons 1202, an earpiece 1204, and amouthpiece 1206, and a display 1208 is disposed between the operationbuttons 1202 and the earpiece 1204. The crystal resonator 100 is builtin such a mobile phone 1200.

As described above, when the mobile phone 1200 (including the PHS) as anexample of the electronic apparatus is provided with the crystalresonator 100 according to the embodiment of the invention, for example,as a clock source, a stable frequency signal is output from the crystalresonator 100 as a clock source which is supplied to the mobile phone1200, and thus it is possible to improve reliability of the operation ofthe mobile phone 1200.

FIG. 15 is a perspective view schematically illustrating a configurationof a digital camera 1300 as an example of the electronic apparatus whichincludes the crystal resonator 100 of the first embodiment. In addition,FIG. 15 briefly illustrates connection between the digital camera 1300and external devices. Here, in a film camera of the related art, asilver-halide photo film is sensitized to light by an optical image ofan object, whereas in the digital camera 1300, an imaging signal (animage signal) is generated by photo-converting an optical image of anobject via an imaging element such as a charge coupled device (CCD).

A display 1304 is provided on a rear surface of a case 1302 (body) inthe digital camera 1300, and performs a display based on the imagingsignal by the CCD, and the display 1304 serves as a finder fordisplaying an object as an electronic image. In addition, a lightreceiving unit 1306 which includes an optical lens (an imaging opticalsystem), a CCD, and the like is provided on the front surface (on therear surface in the drawing) of the case 1302.

When a photographer confirms an object displayed on the display 1304,and presses a shutter button 1308, an imaging signal of the CCD istransferred to and stored in a memory 1310 at the same time. Inaddition, in the digital camera 1300, an output terminal 1312 of a videosignal and an input and output terminal 1314 for data communication areprovided on the side surface of the case 1302. As illustrated in FIG.15, a TV monitor 1410 is connected to the output terminal 1312 of thevideo signal, and a personal computer 1420 is connected to the input andoutput terminal 1314 for data communication as necessary. Further, theimaging signal stored in the memory 1310 is output to the TV monitor1410 or the personal computer 1420 by a predetermined control. Thecrystal resonator 100 is built in such a digital camera 1300.

As described above, when the digital camera 1300 as an example of theelectronic apparatus is provided with the crystal resonator 100according to the embodiment of the invention, for example, as a clocksource, a stable frequency signal is output from the crystal resonator100 as a clock source which is supplied to the digital camera 1300, andthus it is possible to improve reliability of an operation of thedigital camera 1300.

Note that, the crystal resonator 100 of the first embodiment isapplicable to other electronic apparatus in addition to the personalcomputer 1100 (a mobile-type personal computer) in FIG. 13, the mobilephone 1200 in FIG. 14, and the digital camera 1300 in FIG. 15.

Examples of other electronic apparatuss include an ink jet dischargedevice (for example, an ink jet printer), a laptop personal computer, atablet-type personal computer, a storage area network device such as arouter and a switch, local area network equipment, mobile terminal basestation equipment, a television, a video camera, a video recorder, a carnavigation system, a real-time clock device, a pager, an electronicorganizer (including an electronic organizer with a communicationfunction), an electronic dictionary, a calculator, electronic gameequipment, a word processor, a workstation, a videophone, a securitytelevision monitor, an electronic binocular, a POS terminal, medicalequipment (for example, an electronic thermometer, a blood pressuremonitor, a blood glucose meter, an electrocardiogram measuring device,an ultrasonic diagnostic device, and an electronic endoscope), a fishfinder, various measurement equipment, an instrument (for example,instruments of a vehicle, an aircraft, and a ship), a flight simulator,a head-mounted display, a motion trace, a motion tracking, a motioncontroller, and a pedestrian position orientation (PDR).

Ninth Embodiment

Next, a moving object of the ninth embodiment which includes any one ofthe crystal resonators 100, 200, 300, 400, 500, and 600 in the firstembodiment to the sixth embodiment will be described with reference toFIG. 16. In addition, an example of using the crystal resonator 100 ofthe first embodiment as the resonation device is described in thepresent embodiment.

FIG. 16 is a perspective view schematically illustrating an automobile1500 as an example of the moving object which includes the crystalresonator 100 of the first embodiment.

The crystal resonator 100 of the first embodiment is installed in theautomobile 1500. As illustrated in FIG. 16, in the automobile 1500 asthe moving object, the electronic control unit 1510 which includes thecrystal resonator 100 built therein and controls a tire 1504 and thelike is installed in a car body 1502. In addition, the crystal resonator100 according to the embodiment of the invention is widely applicable toan electronic control unit (ECU) for a keyless entry system, animmobilizer, a car navigation system, a car air conditioning system, ananti-lock brake system (ABS), an airbag, a tire pressure monitoringsystem (TPMS), an engine control system, a braking system, a batterymonitor for a hybrid vehicles and an electric vehicle, and a bodyposture control system.

As described above, when the automobile 1500 as an example of the movingobject is provided with the crystal resonator 100 according to theembodiment of the invention, for example, as a clock, a stable frequencysignal is output from the crystal resonator 100 as a clock source whichis supplied to at least one of the automobile 1500 and the electroniccontrol unit 1510, and thus it is possible to improve reliability of theoperations of at least one of the automobile 1500 and the electroniccontrol unit 1510.

What is claimed is:
 1. A resonation device comprising: a substrate; aresonator element that is provided above the substrate, the resonatorelement including: a resonator body configured with a first area and asecond area, the first area having a first area center, the second areasurrounding the first area; first and second excitation electrodessandwiching the first area; first and second connection electrodes thatare electrically connected to the first and second excitationelectrodes, respectively, the first and second connection electrodesbeing provided in the second area along a first direction in a planview; and first and second extracting electrodes that are physicallyelectrically connected between the first and second excitationelectrodes and the first and second connection electrodes, respectively,the first and second extracting electrodes extending in the second areaalong a second direction perpendicular to the first direction; and firstand second bonding members that connect the resonator element to thesubstrate, the first and second bonding members having first and secondbonding centers, the first and second bonding members overlapping withthe first and second connection electrodes in the plan view,respectively, wherein the first area has a first area length in thefirst direction in the plan view, when viewed in the second direction,the first and second extracting electrodes are entirely located withinthe first area length, and when a bonding center length between thefirst and second bonding centers is L1 and a perpendicular length of aperpendicular line drawn to a virtual line which connects the first andsecond bonding centers from the first area center of the first area isL2, a relationship of 0<L1/L2≦0.97 is satisfied.
 2. The resonationdevice according to claim 1, wherein a thickness of the second arealocated between the first and second extracting electrodes in the planview is smaller than a thickness of the first area.
 3. The resonationdevice according to claim 1, wherein a thickness of the second area issmaller than a thickness of the first area.
 4. The resonation deviceaccording to claim 1, wherein each of the first and second excitationelectrodes includes a base layer including at least one type of metal ofnickel and tungsten, and an upper layer including at least one type ofmetal among gold, platinum, silver, aluminum, and copper on the baselayer.
 5. The resonation device according to claim 1, wherein arelationship of 0<L1/L2≦0.85 is satisfied.
 6. The resonation deviceaccording to claim 1, wherein a relationship of 0.185<L1/L2≦0.97 issatisfied.
 7. The resonation device according to claim 1, wherein arelationship of 0.425<L1/L2≦0.97 is satisfied.
 8. The resonation deviceaccording to claim 1, wherein the first and second bonding members haveconductivity.
 9. The resonation device according to claim 1, wherein atleast one of the first bonding member and the second bonding member is ametallic bump.
 10. An oscillator comprising: the resonation deviceaccording to claim 1, the resonation device having a lid, the resonatorelement is enclosed by the lid and the substrate; an oscillation circuitthat is connected to the resonation device via a first conductor; and acontainer that accommodates the resonation device and the oscillationcircuit.
 11. An oscillator comprising: the resonation device accordingto claim 2, the resonation device having a lid, the resonator element isenclosed by the lid and the substrate; an oscillation circuit that isconnected to the resonation device via a first conductor; and acontainer that accommodates the resonation device and the oscillationcircuit.
 12. An oscillator comprising: the resonation device accordingto claim 3, the resonation device having a lid, the resonator element isenclosed by the lid and the substrate; an oscillation circuit that isconnected to the resonation device via a first conductor; and acontainer that accommodates the resonation device and the oscillationcircuit.
 13. An oscillator comprising: the resonation device accordingto claim 4, the resonation device having a lid, the resonator element isenclosed by the lid and the substrate; an oscillation circuit that isconnected to the resonation device via a first conductor; and acontainer that accommodates the resonation device and the oscillationcircuit.
 14. The oscillator according to claim 10, wherein the lid andthe oscillation circuit are connected to each other via the firstconductor.
 15. The oscillator according to claim 11, wherein the lid andthe oscillation circuit are connected to each other via the firstconductor.
 16. The oscillator according to claim 12, wherein the lid andthe oscillation circuit are connected to each other via the firstconductor.
 17. The oscillator according to claim 13, wherein the lid andthe oscillation circuit are connected to each other via the firstconductor.
 18. An electronic apparatus comprising the resonation deviceaccording to claim
 1. 19. A moving object comprising the resonationdevice according to claim 1.